Battle of Iwo Jima officially ends, with the destruction of the remaining areas of Japanese resistance, although there are Japanese holdouts here until 1949. March 27 – WWII: The United States Army Air Forces begins Operation Starvation, laying naval mines in many of Japan's seaways. Argentina declares war on Germany and Japan. March 29 WWII: The Red Army almost destroys the German 4th Army, in the Heiligenbeil Pocket in East Prussia. The "Clash of Titans": George Mikan and Bob Kurland duel at Madison Square Garden in New York, as Oklahoma State University defeats DePaul 52–44 in basketball. March 30 – WWII: The Red Army pushes most of the Axis forces out of Hungary into Austria. American official Alger Hiss is congratulated in Moscow for his part in bringing the positions of the Western powers and the Soviet Union closer to each other, at the Yalta Conference. April April 1 – WWII: Battle of Okinawa: The Tenth United States Army lands on Okinawa. April 4 – WWII: American troops liberate their first Nazi concentration camp, Ohrdruf extermination camp in Germany. The Red Army enters Bratislava and pushes to the outskirts of Vienna, taking it on April 13, after several days of intense fighting. April 6 – WWII: Sarajevo is liberated from Nazi Germany and the Independent State of Croatia (a fascist puppet state), by Yugoslav Partisans. The Battle of Slater's Knoll on Bougainville Island concludes, with a decisive victory for the Australian Army's 7th Brigade. Allied forces reach Merkers Salt Mines in Thuringia, where gold reserves of the Nazi German Reichsbank are stored. April 7 – WWII: The only flight of the German ramming unit known as Sonderkommando Elbe takes place, resulting in the loss of some 24 B-17s and B-24s of the United States Eighth Air Force. and nine other warships take part in Operation Ten-Go, a suicide attack on Allied forces engaged in the Battle of Okinawa. Yamato is sunk by U.S. Navy aircraft in the East China Sea north of Okinawa with the loss of 2,055 of 2,332 crew, together with five other Japanese warships. Kantarō Suzuki becomes Prime Minister of Japan. April 8 – The SS begins to evacuate the Buchenwald concentration camp; inmates in the Buchenwald Resistance call for American aid, and overpower and kill the remaining guards. April 9 WWII: The Battle of Königsberg, in East Prussia, ends with Soviet forces capturing the city. Abwehr