The Battle of Berlin, designated the Berlin Strategic Offensive Operation by the Soviet Union, was the final major offensive of the European theatre of World War II. When the Soviet offensive resumed on 16 April, two Soviet fronts (army groups) attacked Berlin from the east and south, while a third overran German forces positioned north of Berlin. Before the main battle in Berlin commenced, the Red Army encircled the city after successful battles of the Seelow Heights and Halbe. On 20 April 1945, the 1st Belorussian Front led by Marshal Georgy Zhukov started shelling Berlin's city centre, while Marshal Ivan Konev's 1st Ukrainian Front had pushed from the south through the last formations of Army Group Centre. Concurrently, Hitler called for the activation of Operation Clausewitz on the same date. Defenses in Berlin's city center were mainly led by General Helmuth Weidling. These units consisted of several depleted and disorganized Wehrmacht and Waffen-SS divisions, along with poorly trained Volkssturm and Hitler Youth members. Within the next few days, the Red Army reached the city centre where close-quarters combat raged. Before the battle was over, German Führer Adolf Hitler and many other major officials of the Nazi regime committed suicide. The city's garrison surrendered on 2 May, but fighting continued to the north-west, west, and south-west of the city until the end of the war in Europe on 8 May (9 May in the Soviet Union) as German units fought westward so that they could surrender to the Western Allies rather than to the Soviets.