As a continuation of the Leningrad–Novgorod Offensive of January 1944, the Soviet Estonian operation pushed the front westward to the Narva River, aiming to destroy "Narwa" and to thrust deep into Estonia. The Soviet units established a number of bridgeheads on the western bank of the river in February while the Germans maintained a bridgehead on the eastern bank. Subsequent attempts failed to expand their toehold. German counterattacks annihilated the bridgeheads to the north of Narva and reduced the bridgehead south of the town, stabilizing the front until July 1944. The Soviet Narva Offensive (July 1944) led to the capture of the city after the German troops retreated to their prepared Tannenberg Defence Line in the Sinimäed Hills 16 kilometres from Narva. In the ensuing Battle of Tannenberg Line, the German army group held its ground. Stalin's main strategic goal—a quick recovery of Estonia as a base for air and seaborne attacks against Finland and an invasion of East Prussia—was not achieved. As a result of the tough defence of the German forces the Soviet war effort in the Baltic Sea region was hampered for seven and a half months.