U.S. Bombers Blast German Installations In Yugoslavia. Soaring high above scattered clouds, a squadron of B-25 Mitchell medium bombers of the Twelfth U.S. Amy Air Force blasts the port of Sibenik, Yugoslavia, damaging the German-held airfield, railway yards and supply depots. Raids by Allied pianos over German supply bases and communication lines are helping Yugoslav patriots in their fight against the invader. February 14, 1944.