Third Battle of Kharkov The Third Battle of Kharkov was a series of battles on the Eastern Front of World War II , undertaken by the German Army Group South against the Red Army , around the city of Kharkov ( now " Kharkiv " ) between 19 February and 15 March 1943 . Known to the Germans as the Donets Campaign , and to the Soviets as the Donbas and Kharkov operations , the German counterstrike led to the destruction of approximately 52 Soviet divisions and the recapture of the cities of Kharkov and Belgorod . As the German Sixth Army was encircled in Stalingrad , the Red Army undertook a series of wider attacks against the rest of Army Group South . These culminated on 2 January 1943 when the Soviets launched Operation " Star " and Operation " Gallop " , which between January and early February broke German defenses and led to the Soviet recapture of Kharkov , Belgorod , Kursk , as well as Voroshilovgrad and Izium . The Soviet victories caused participating Soviet units to over - extend themselves . Freed on 2 February by the surrender of the German Sixth Army the Red Army ' s Central Front turned its attention west and on 25 February expanded its offensive against both Army Group South and Army Group Center . Months of continuous operations , however , had taken a heavy toll on the Soviets and some divisions were reduced to 1 , 000 – 2 , 000 combat effective soldiers . On 19 February , Field Marshal Erich von Manstein launched his Kharkov counterstrike , using the fresh SS Panzer Corps and two panzer armies . The " Wehrmacht " , while also understrength , flanked , encircled , and defeated the Red Army ' s armored spearheads south of Kharkov . This enabled von Manstein to renew his offensive against the city of Kharkov proper on 7 March . Despite orders to encircle Kharkov from the north the SS Panzer Corps instead decided to directly engage Kharkov on 11 March . This led to four days of house - to - house fighting before Kharkov was recaptured by the 1st SS Panzer Division on 15 March . The Germans recaptured Belgorod two days later , creating the salient which in July 1943 would lead to the Battle of Kursk . The German offensive cost the Red Army an estimated 70 , 000 casualties . The house - to - house fighting in Kharkov was also particularly bloody for the German SS Panzer Corps , which had lost approximately 4 , 300 men by the time operations ended in mid March . Background . At the start of 1943 , the German " Wehrmacht " faced a crisis as Soviet forces encircled and reduced the German Sixth Army at Stalingrad and expanded their Winter Campaign towards the Don River . On 2 February 1943 the Sixth Army ' s commanding officers surrendered , and an estimated 90 , 000 men were captured by the Red Army . Total German losses at the Battle of Stalingrad , excluding prisoners , were between 120 , 000 and 150 , 000 . Throughout 1942 German casualties totaled around 1 . 9 million personnel , and by the start of 1943 the " Wehrmacht " was around 470 , 000 men below full strength on the Eastern Front . At the beginning of Operation " Barbarossa " , the " Wehrmacht " was equipped with around 3 , 300 tanks ; by 23 January only 495 tanks , mostly of older types , remained operational along the entire length of the Soviet – German front . As the forces of the Don Front were destroying the German forces in Stalingrad , Stavka ordered the Soviet forces to conduct a new offensive , which encompassed the entire southern wing of the Soviet – German front from Voronezh to Rostov . On 2 February , the Red Army launched Operation " Star " , threatening to recapture the cities of Belgorod , Kharkov and Kursk . A Soviet drive , spearheaded by four tank corps organized under Lieutenant - General Markian Popov , pierced the German front by crossing the Donets River and pressing into the German rear . On 15 February , two fresh Soviet tank corps threatened the city of Zaporizhia on the Dnieper River , which controlled the last major road to Rostov and housed the headquarters of Army Group South and " Luftflotte 4 " ( Air Fleet Four ) . Despite Hitler ' s orders to hold the city , Kharkov was abandoned by German forces and the city was recaptured by the Red Army on 16 February . Hitler immediately flew to von Manstein ' s headquarters at Zaporizhia . Von Manstein informed him that an immediate counterattack on Kharkov would be fruitless , but that he could successfully attack the overextended Soviet flank with his five Panzer Corps , and recapture the city later . On 19 February Soviet armored units broke through the German lines and approached the city . In view of the worsening situation , Hitler gave Manstein operational freedom . When Hitler departed , the Soviets were only some away from the airfield . In conjunction with Operation " Star " the Soviets also launched Operation Gallop south of " Star " , pushing the Germans away from the Donets , taking Voroshilovgrad and Izium , worsening the German situation further . By this time Stavka believed it could decide the war in Southern Russia , expecting total victory . The surrender of the German Sixth Army at Stalingrad freed six Soviet armies , under the command of Konstantin Rokossovsky , which were refitted and reinforced by the 2nd Tank Army and the 70th Army . These forces were repositioned between the junction of German Army Groups Center and South . Known to the Soviets as the Kharkov and Donbas operations , the offensive sought to surround and destroy German forces in the Orel salient , cross the Desna River and surround and destroy German Army Group Center . Originally planned to begin between 12 – 15 February , deployment problems forced the Red Army ' s command ( " Stavka " ) to push the start date back to 25 February . Meanwhile , the Soviet 60th Army pushed the German Second Army ' s 4th Panzer Division away from Kursk , while the Soviet 13th Army forced the Second Panzer Army to turn on its flank . This opened a breach between these two German forces , shortly to be exploited by Rokossovsky ' s offensive . While the Soviet 14th and 48th Armies attacked the Second Panzer Army ' s right flank , making minor gains , Rokossovsky launched his offensive on 25 February , breaking through German lines and threatening to surround and cut off the German Second Panzer Army and the Second Army , to the south . However , unexpected German resistance began to slow the operation considerably , offering Rokossovsky only limited gains on the left flank of his attack and in the center . Elsewhere , the Soviet 2nd Tank Army had successfully penetrated of the German rear , along the left flank of the Soviet offensive , increasing the length of the army ' s flank by an estimated . While the Soviet offensive continued , Field Marshal von Manstein was able to put the SS Panzer Corps — now reinforced by the 3rd SS Panzer Division — under the command of the Fourth Panzer Army , while Hitler agreed to release seven understrength panzer and motorized divisions for the impending counteroffensive . The Fourth Air Fleet , under the command of Field Marshal Wolfram von Richthofen , was able to regroup and increase the amount of daily sorties from an average of 250 in January to 1 , 000 in February , providing German forces strategic air superiority . On 20 February , the Red Army was perilously close to Zaporizhia , signaling the beginning of the German counterattack , known to the Germans as the Donets Campaign . Comparison of forces . Between 13 January and 3 April 1943 , an estimated 500 , 000 Red Army soldiers took part in what was known as the Voronezh – Kharkov Offensive . In all , an estimated 6 , 100 , 000 Soviet soldiers were committed to the area , with another 659 , 000 out of action with wounds . In comparison , the Germans could account for 2 , 200 , 000 personnel on the Eastern Front , with another 100 , 000 deployed in Norway . As a result , the Soviets deployed around twice as many personnel as the " Wehrmacht " in early February . However , as a result of their over - extension and the casualties they had taken during their offensive , at the beginning of Manstein ' s counterattack the Germans could achieve a tactical superiority in numbers , including the number of tanks present — for example , Manstein ' s 350 tanks outnumbered Soviet armor almost seven to one at the point of contact . German forces . At the time of the counterattack , Manstein could count on the Fourth Panzer Army , composed of XLVIII Panzer Corps , the SS Panzer Corps and the First Panzer Army , with the XL and LVII Panzer Corps . The XLVIII Panzer Corps was composed of the 6th , 11th and 17th Panzer Divisions , while the SS Panzer Corps was organized with the 1st SS , 2nd SS and 3rd SS Panzer Division . In early February , the combined strength of the SS Panzer Corps was an estimated 20 , 000 soldiers . The Fourth Panzer Army and the First Panzer Army were situated south of the Red Army ' s bulge into German lines , with the First Panzer Army to the east of the Fourth Panzer Army . The SS Panzer Corps was deployed along the northern edge of the bulge , on the northern front of Army Group South . The Germans were able to amass around 70 , 000 men against the 210 , 000 Red Army soldiers . The German " Wehrmacht " was understrength , especially after continuous operations between June 1942 and February 1943 , to the point where Hitler appointed a committee made up of Field Marshal Wilhelm Keitel , Martin Bormann and Hans Lammers , to recruit 800 , 000 new able - bodied men — half of whom would come from " nonessential industries " . However , the effects of this recruitment were not seen until around May 1943 , when the German armed forces were at their highest strength since the beginning of the war , with 9 . 5 million personnel . By the start of 1943 Germany ' s armored forces had sustained heavy casualties . It was unusual for a Panzer Division to field more than 100 tanks , and most averaged only 70 – 80 serviceable tanks at any given time . After the fighting around Kharkov , Heinz Guderian embarked on a program to bring Germany ' s mechanized forces up to strength . Despite his efforts , a German panzer division could only count on an estimated 10 , 000 – 11 , 000 personnel , out of an authorized strength of 13 , 000 – 17 , 000 . Only by June did a panzer division begin to field between 100 – 130 tanks each . SS divisions were normally in better shape , with an estimated 150 tanks , a battalion of self - propelled assault guns and enough half - tracks to motorize most of its infantry and reconnaissance soldiers — and these had an authorized strength of an estimated 19 , 000 personnel . At this time , the bulk of Germany ' s armor was still composed of Panzer III s and Panzer IV s , although the 2nd SS Panzer Division had been outfitted with a number of Tiger I tanks . The Fourth Panzer Army was commanded by General Hermann Hoth , while the First Panzer Army fell under the leadership of General Eberhard von Mackensen . The 6th , 11th and 17th Panzer Divisions were commanded by Generals Walther von Hünersdorff , Hermann Balck and Fridolin von Senger und Etterlin , respectively . The SS Panzer Corps was commanded by General Paul Hausser , who also had the 3rd SS Panzer ( Totenkopf ) Division under his command . Red Army . Since the beginning of the Red Army ' s exploitation of Germany ' s Army Group South ' s defenses in late January and early February , the fronts involved included the Bryansk , Voronezh and Southwestern Fronts . These were under the command of Generals M . A . Reiter , Filipp Golikov and Nikolai Vatutin , respectively . On 25 February , Marshal Rokossovsky ' s Central Front also joined the battle . These were positioned in such a way that Reiter ' s Briansk Front was on the northern flank of Army Group South , while Voronezh was directly opposite of Kursk , and the Southwestern Front was located opposite their opponents . Central Front was deployed between the Briansk and Voronezh Fronts , to exploit the success of both of these Soviet units , which had created a gap in the defenses of the German Second Panzer Army . This involved an estimated 500 , 000 soldiers , while around 346 , 000 personnel were involved in the defense of Kharkov after the beginning of the German counterstroke . Like their German counterparts , Soviet divisions were also seriously understrength . For example , divisions in the 40th Army averaged 3 , 500 – 4 , 000 men each , while the 69th Army fielded some divisions which could only count on 1 , 000 – 1 , 500 soldiers . Some divisions had as little as 20 – 50 mortars to provide fire support . This shortage in manpower and equipment led Vatutin ' s Southwestern Front to request over 19 , 000 soldiers and 300 tanks , while it was noted that the Voronezh Front had only received 1 , 600 replacements since the beginning of operations in 1943 . By the time Manstein launched his counteroffensive , the Voronezh Front had lost so much manpower and had overextended itself to the point where it could no longer offer assistance to the Southwestern Front , south of it . Manstein ' s counterattack . What was known to the Germans as the Donets Campaign took place between 19 February and 15 March 1943 . Originally , Manstein foresaw a three - stage offensive . The first stage encompassed the destruction of the Soviet spearheads , which had over - extended themselves through their offensive . The second stage included the recapture of Kharkov , while the third stage was designed to attack the Soviets at Kursk , in conjunction with Army Group Center — this final stage was ultimately called off due to the advent of the Soviet spring thaw ( " Rasputitsa " ) and Army Group Center ' s reluctance to participate . First stage : 19 February – 6 March . On 19 February , Hausser ' s SS Panzer Corps was ordered to strike southwards , to provide a screen for the 4th Panzer Army ' s attack . Simultaneously , Army Detachment Hollidt was ordered to contain the continuing Soviet efforts to break through German lines . The 1st Panzer Army was ordered to drive north in an attempt to cut off and destroy Popov ' s Mobile Group , using accurate intelligence on Soviet strength which allowed the Germans to pick and choose their engagements and bring about tactical numerical superiority . The 1st and 4th Panzer Armies were also ordered to attack the overextended Soviet 6th Army and 1st Guards Army . Between 20 – 23 February , the 1st SS Panzer Division " LSSAH " cut through the 6th Army ' s flank , eliminating the Soviet threat to the Dnieper River and successfully surrounding and destroying a number of Red Army units south of the Samara River . The 2nd SS Panzer Division " Das Reich " advanced in a northeastern direction , while the 3rd SS Panzer Division " Totenkopf " was put into action on 22 February , advancing parallel to the Das Reich . These two divisions successfully cut the supply lines to the Soviet spearheads . First Panzer Army was able to surround and pocket Popov ' s Mobile Group by 24 February , although a sizable contingent of Soviet troops managed to escape north . On 22 February , alarmed by the success of the German counterattack , the Soviet " Stavka " ordered the Voronezh Front to shift the 3rd Tank Army and 69th Army south , in an effort to alleviate pressure on the Southwestern Front and destroy German forces in the Krasnograd area . The Red Army ' s 3rd Tank Army began to engage German units south of Kharkov , performing a holding action while Manstein ' s offensive continued . By 24 February , the Germans had pulled the " Großdeutschland " Panzergrenadier Division off the line , leaving the 167th and 320th infantry divisions , a regiment from the Totenkopf division and elements from the Leibstandarte division to defend the Western edge of the bulge created by the Soviet offensive . Between 24 – 27 February , the 3rd Tank Army and 69th Army continued to attack this portion of the German line , but without much success . With supporting Soviet units stretched thin , the attack began to falter . On 25 February , Rokossovky ' s Central Front launched their offensive between the German Second and Third Panzer Armies , with encouraging results along the German flanks , but struggling to keep the same pace in the center of the attack . As the offensive progressed , the attack on the German right flank also began to stagnate in the face of increased resistance , while the attack on the left began to over - extend itself . In the face of German success against the Southwestern Front , including attempts by the Soviet 6th Army breaking out of the encirclement , " Stavka " ordered the Voronezh Front to relinquish control of the 3rd Tank Army to the Southwestern Front . To ease the transition , the 3rd Tank Army gave two rifle divisions to the 69th Army , and attacked south in a bid to destroy the SS Panzer Corps . However , low on fuel and ammunition after the march south , the 3rd Tank Army ' s offensive was postponed until 3 March . Furthermore , the 3rd Tank Army was harassed and severely damaged by continuous German aerial attacks with Junkers Ju 87 " Stuka " dive bomber s . Launching its offensive on 3 March , the 3rd Tank Army ' s 15th Tank Corps struck into advancing units of the 3rd SS Panzer Division and immediately went to the defensive . Ultimately , the 3rd SS was able to pierce the 15th Tank Corps ' lines and link up with other units of the same division advancing north , successfully encircling the Soviet tank corps . The 3rd Tank Army ' s 12th Tank Corps was also forced on the defensive immediately , after the 1st and 2nd SS Panzer Divisions threatened to cut off the 3rd Tank Army ' s supply route . By 5 March , the attacking 3rd Tank Army had been badly mauled , with only a small amount of men able to escape northwards , and was forced to erect a new defensive line . The destruction of Popov ' s Mobile Group and the 6th Army during the early stages of the German counterattack created a large gap between Soviet lines . Taking advantage of uncoordinated and piecemeal Soviet attempts to plug this gap , Manstein ordered a continuation of the offensive towards Kharkov . Between 1 – 5 March the 4th Panzer Army , including the SS Panzer Corps , covered and positioned itself only about south of Kharkov . By 6 March , the 1st SS Panzer Division made a bridgehead over the Mosh River , opening the road to Kharkov . The success of Manstein ' s counterattack forced " Stavka " to stop Rokossovsky ' s offensive . The First Panzer Army was able to regain a defensive line on the Donets River , and Manstein began to plan subsequent attacks to clear Soviet units west of the Donets . According to the Germans , the German counterattack had cost the Red Army an estimated 23 , 000 soldiers dead , along with 615 tanks and 352 artillery pieces lost . Advance towards Kharkov : 7 – 10 March . While Rokossovsky ' s Central Front continued its offensive against the German Second Army , which had by now been substantially reinforced with fresh divisions , the renewed German offensive towards Kharkov took it by surprise . On 7 March , Manstein made the decision to press on towards Kharkov , despite the coming of the spring thaw . Instead of attacking east of Kharkov , however , Manstein decided to orient the attack towards the west of Kharkov and then encircle it from the north . The " Grossdeutschland " Panzergrenadier Division had also returned to the front , and threw its weight into the attack , threatening to split the 69th Army and the remnants of the 3rd Tank Army . Between 8 – 9 March , the SS Panzer Corps completed its drive north , splitting the 69th and 40th Soviet Armies , and on 9 March it turned east to complete its encirclement . Despite attempts by the " Stavka " to curtail the German advance by throwing in the freshly released 19th Rifle Division and 186th Tank Brigade , the German drive continued . On 9 March , the Soviet 40th Army counterattacked against the " Grossdeutschland " Division in a final attempt to restore communications with the 3rd Tank Army . This counterattack , however , was caught by the expansion of the German offensive towards Kharkov on 10 March . That same day , the 4th Panzer Army issued orders to the SS Panzer Corps to take Kharkov as soon as possible , prompting Hausser to order an immediate attack on the city by the three SS Panzer divisions . The " Das Reich " would come from the West , the " LSSAH " would attack from north , and the " Totenkopf " would provide a protective screen along the north and northwestern flanks . Despite attempts by General Hoth to order Hausser to stick to the original plan , the SS Panzer Corps ' commander decided to continue with his own plan of attack on the city , although Soviet defenses forced him to postpone the attack until the next day . Manstein issued an order to continue outflanking the city , although leaving room for a potential attack on Kharkov if there was little Soviet resistance , but Hausser decided to disregard the order and continue with his own assault . According to von Manstein , the Army Group headquarters was forced to intervene on a number of occasions to bring the SS Panzer Corps to swing eastwards to encircle the city , instead of launching a frontal attack on Kharkov . Fight for the city : 11 – 15 March . Early morning 11 March , the " LSSAH " launched a two - prong attack into northern Kharkov . The 2nd Panzergrenadier Regiment , advancing from the Northwest , split up into two columns advancing towards northern Kharkov on either side of the Belgorod - Kharkov railroad . The 2nd Battalion , on the right side of the railroad , attacked the city ' s Severnyi Post district , meeting heavy resistance and advancing only to the Severenyi railway yard by the end of the day . On the opposite side of the railroad , the 1st Battalion struck at the district of Alexeyevka , meeting a T - 34 - led Soviet counterattack which drove part of the 1st Battalion back out of the city . Only with aerial and artillery support , coming from Ju 87 " Stuka " dive bombers and StuG assault guns , were the German infantry able to battle their way into the city . A flanking attack from the rear finally allowed the Germans to achieve a foothold in that area of the city . Simultaneously , the 1st SS Panzergrenadier Regiment , with armor attached from a separate unit , attacked down the main road from Belgorod , fighting an immediate counterattack produced over the Kharkov ' s airport , coming on their left flank . Fighting their way past Soviet T - 34 s , this German contingent was able to lodge itself into Kharkov ' s northern suburbs . From the northeast , another contingent of German infantry , armor and self - propelled guns attempted to take control of the road exits to the cities of Rogan and Chuhuiv . This attack penetrated deeper into Kharkov , but low on fuel the armor was forced to entrench itself and turn to the defensive . The " Das Reich " division attacked on the same day , along the west side of Kharkov . After penetrating into the city ' s Zalyutino district , the advance was stopped by a deep anti - tank ditch , lined with Soviet defenders , including anti - tank guns . A Soviet counterattack was repulsed after a bloody firefight . A detachment of the division fought its way to the southern approaches of the city , cutting off the road to Merefa . At around 15 : 00 , Hoth ordered Hausser to immediately disengage with the " Das Reich " , and instead redeploy to cut off escaping Soviet troops . Instead , Hausser sent a detachment from the " Totenkopf " division for this task and informed Hoth that the risk of disengaging with the " Das Reich " was far too great . On the night of 11 – 12 March , a breakthrough element crossed the anti - tank ditch , taking the Soviet defenders by surprise , and opening a path for tanks to cross . This allowed the " Das Reich " to advance to the city ' s main railway station , which would be the farthest this division would advance into the city . Hoth repeated his order at 00 : 15 , on 12 March , and Hausser replied as he had replied on 11 March . However , a third attempt by Hoth was obeyed , and " Das Reich " disengaged , using a corridor opened by " LSSAH " to cross northern Kharkov and redeploy east of the city . On 12 March , the " LSSAH " made progress into the city ' s center , breaking through the staunch Soviet defenses in the northern suburbs and began a house to house fight towards the center . By the end of the day , the division had reached a position just two blocks north of Dzerzhinsky Square . The 2nd Panzergrenadier Regiment ' s 2nd Battalion was able to surround the square , after taking heavy casualties from Soviet snipers and other defenders , by evening . When taken , the square was renamed " " Platz der Leibstandarte " " . That night , 2nd Panzergrenadier Regiment ' s 3rd Battalion , under the command of Joachim Peiper linked up with the 2nd Battalion in Dzerzhinsky Square and attacked southwards , crossing the Kharkiv River and creating a bridgehead , opening the road to Moscow Avenue . Meanwhile , the division ' s left wing reached the junction of the Volchansk and Chuhuiv exit roads and went on the defensive , fighting off a number of Soviet counterattacks . The next day , the " LSSAH " struck southwards towards the Kharkov River from Peiper ' s bridgehead , clearing Soviet resistance block by block . In a bid to trap the city ' s defenders in the center , the 1st Battalion of the 1st SS Panzergrenadier Regiment re - entered the city using the Volchansk exit road . At the same time , Peiper ' s forces were able to breakout south , suffering from bitter fighting against a tenacious Soviet defense , and link up with the division ' s left wing at the Volchansk and Chuhuiv road junction . Although the majority of " Das Reich " had , by now , disengaged from the city , a single Panzergrenadier Regiment remained to clear the southwestern corner of the city , eliminating resistance by the end of the day . This effectively put two - thirds of the city under German control . Fighting in the city began to wind down on 14 March . The day was spent with the " LSSAH " clearing the remnants of Soviet resistance , pushing east along a broad front . By the end of the day , the entire city was declared to be back in German hands . Despite the declaration that the city had fallen , fighting continued on 15 and 16 March , as German units cleared the remnants of resistance in the tractor works factory complex , in the southern outskirts of the city . Aftermath . Army Group South ' s Donets Campaign had cost the Red Army some 52 divisions , including over 70 , 000 – 80 , 000 personnel casualties . Of these troops lost , an estimated 45 , 200 were killed or went missing , while another 41 , 200 were wounded . Between April and July 1943 , the Red Army took its time to rebuild its forces in the area and prepare for an eventual renewal of the German offensive , known as the Battle of Kursk . Overall German casualties are more difficult to come by but clues are provided by examining the casualties of the SS Panzer Corps , taking into consideration that the elite " Waffen - SS " divisions were frequently deployed where the fighting was expected to be the harshest . By 17 March , it is estimated that the SS Panzer Corps had lost around 44 % of its fighting strength , including around 160 officers and about 4 , 300 enlisted personnel . As the SS Panzer Corps began to emerge from the city , they engaged Soviet units positioned directly southwest of the city , including the 17th NKVD Brigade , 19th Rifle Division and 25th Guards Rifle Division . Attempts by the Red Army to re - establish communication with the remnants of the 3rd Tank Army continued , although in vain . On 14 – 15 March these forces were given permission to withdraw to the northern Donets River . The Soviet 40th and 69th armies had been engaged since 13 March with the Grossdeutschland Panzergrenadier Division , and had been split by the German drive . After the fall of Kharkov the Soviet defense of the Donets had collapsed , allowing Manstein ' s forces to drive to Belgorod on 17 March , and take it by the next day . However , weather and exhaustion forced Manstein ' s counterstroke to end soon thereafter , despite the Field Marshal ' s ambitions to also attack the Kursk salient which had been created as a result of the recapture of Kharkov and Belgorod . One historian wrote that the Third Battle of Kharkov was " the last great victory of German arms in the eastern front . " Experts on a documentary series even argued that German victory in the battle had delayed the advance of the Red Army into Germany by at least six months . Following the German success at Kharkov , Hitler was presented with two options . The first , known as the " backhand method " was to wait for the inevitable renewal of the Soviet offensive and conduct another operation similar to that of Kharkov — allowing the Red Army to take ground , extend itself and then counterattack and surround it . The second , or the " forehand method " , encompassed a major German offensive by Army Groups South and Center against the protruding Kursk salient . Typically , Hitler chose the " forehand method " , which led to the Battle of Kursk .