In Belarusian Morgues and Hospitals, Clues to Russian Military Losses in UkraineThere's no room in the morgue at Mazyr. It's filled with the bodies of Russian soldiers. At one hospital in this Belarusian city about 60 kilometers from the border with Ukraine, the hallways and wards are filled with the sounds of soldiers moaning from their battlefield wounds. At the main train station, Russian soldiers have been recorded on video ferrying stretchers — apparently holding wounded servicemen — from a military ambulance to a waiting train operated by Russia's state railway company. And in Naroulya, a town still closer to the Ukrainian border, residents report that a Russian field hospital has been set up in a former motor depot, and wounded Russian soldiers are being flown in from Ukraine, treated briefly, then shipped on to Mazyr and the regional capital, Homel. Now in its fourth week, Russia's war in Ukraine continues to extract a horrific toll on Ukrainian civilians and soldiers on both sides. Some of the deadliest attacks and fighting have happened near the Belarusian border close to Homel; near the Russian border in Kharkiv and Sumy in the east; and around southern port cities such as Mariupol and Kherson. Full and reliable casualty counts have been hard to come by. Among civilians, the United Nations has recorded 780 killed and more than 1,250 wounded — but it estimates that the actual figures are much higher, and Ukrainian officials say thousands of civilians have been killed. The toll among combatants has also proved elusive, with experts saying each side seeks to exaggerate the losses of the enemy and minimize its own. In Russia, coming up with an accurate tally is even harder, due to government regulations that have clamped down on independent reporting — and even made uttering the words "war" and "invasion" a potentially criminal offense. But in the Belarusian regions bordering Ukraine, residents and medical workers have reported a rising tide of corpses and maimed servicemen being shipped out of Ukraine and then sent elsewhere for further treatment — or burial. More than 2,500 soldiers' corpses had already been shipped from the Homel region back to Russia by trains or by plane as of March 13, according to one employee of the Homel regional clinical hospital. Like all the people who spoke with RFE/RL, this individual asked not to be named out of fear of retribution or prosecution by Belarusian or Russian security agencies. The figure could not be independently verified. 'It Was Unbelievable How Many Corpses There Were' Ukraine's military claims that more than 14,000 Russians have been killed since Russia launched the invasion on February 24 -- a number that is much higher than most independent estimates. The military has not released formal casualty figures, saying it is a state secret, but President Volodymyr Zelenskyy said last week that about 1,300 Ukrainian soldiers had been killed. Russia's Defense Ministry, meanwhile, claims that more than 2,870 Ukrainian soldiers and paramilitary fighters have been killed, and around 3,700 wounded. Its only official tally of Russian casualties came on March 2, when the ministry said that 498 soldiers had been killed and 1,597 wounded. Earlier this week, U.S. intelligence put the Russian military death toll at more than 7,000 — and said that is a conservative estimate. One place to look for evidence of Russian military deaths is the Homel region: Wedged into southeastern Belarus, it borders Russia to the east and Ukraine to the south. The city of Homel is Belarus's largest after Minsk, and a major hub for trade and transport. Under strongman leader Alyaksandr Lukashenka, Belarus has increasingly become a vassal state of Russia, according to experts. Lukashenka has voiced strong backing for Russia's war, allowed deployment of major Russian military units in the country, and threatened to send Belarusian forces into Ukraine. Before the invasion, tens of thousands of Russian troops were positioned close to the Ukrainian border. An unknown number of them crossed from the Homel region and pushed south toward Kyiv, but they have advanced slowly and suffered substantial losses. In Mazyr, whose population is around 100,000, the city's only morgue was overflowing with corpses as of March 3, according to eyewitnesses. "It was unbelievable how many corpses there were," said one Mazyr resident who frequently drives through the city and nearby areas for business. WATCH: Russian forces are meeting fierce resistance and taking casualties as they try to move towards the Ukrainian capital, Kyiv. On March 18, a Ukrainian special search group collected the dead bodies of Russian soldiers in the hope they could be exchanged for Ukrainian prisoners of war.  He said he had seen many "black sacks" being loaded from military ambulances onto Russian railway cars. "Passengers at the Mazyr train station were shocked by the number of corpses being loaded on the train," he said. "After people started shooting video, the military caught them and ordered them to remove it." In Homel, the regional capital, a laboratory for the city's main hospital was refitted earlier this month, with existing equipment being moved out and beds and other medical equipment being brought in, residents said. Homel residents told RFE/RL that wounded Russian soldiers were being brought to three separate medical facilities in the city, including one specializing in cancer treatment. A doctor at Mazyr's main city hospital told RFE/RL that the facility was now under guard by police and security agencies, and that doctors had been threatened with firing if they spoke about conditions. The doctor said that all physicians on staff, even those from more specialized professions, had been tasked with treating wounded Russians. "There are not enough surgeons. Earlier, the corpses were transported by ambulances and loaded on Russian trains," the doctor said. "After someone made a video about it and it went on the Internet, the bodies were loaded at night so as not to attract attention." At Hospital No. 4 in Homel, officials began to discharge current patients on March 1 in order to make room for wounded Russians, according to multiple residents whom RFE/RL spoke to. "There are so many wounded Russians there -- it's just a horror. Terribly disfigured. It is impossible to listen to their moans throughout the whole hospital," said one resident who was treated in the Homel hospital. Another Homel doctor said there was growing concern among city residents that there could be shortage of everyday medications for the general population. "People are panicking, but so far there is [medical] help and there is enough medicine. What will happen next is still unknown," the doctor said. "It's likely there will be problems with anti-tetanus drugs." Tetanus is a common ailment afflicting soldiers suffering from shrapnel and bullet wounds. At Homel's Center for Radiation Medicine, about 400 Russian troops are currently being treated, according to employees. The influx of troops has also prompted at least one hospital employee to call for donations — of diapers, wet wipes, soap, shampoo, water, cookies, and clothes to help the soldiers. Hanna Krasulina, a spokeswoman for exiled Belarusian opposition leader Svyatlana Tsikhanouskaya, told Ukrainian television on March 2 that morgues in Mazyr were crowded with dead Russian servicemen, some of them from Chechnya. "We must inform both the Chechens and the Russians that the Belarusian morgues in the south of Belarus are already being filled with the corpses of their soldiers," she said. "This is important to let them know. We will not allow Russian propaganda to hide it."