In the first air raid ofBosnian Serbssince last November,NATOwarplanes bombed an ammunition depot near the Bosnian Serb headquarters of Pale, in an attempt to force the Serbs to end their siege of Sarajevo. The planes, including some from the U.S., carried out the raid several hours after a deadline had passed for the Serbs to stop their shelling of Sarajevo and return heavy weapons toU.N. control. There were no casualties reported in the attack, and it did not appear to discourage the Serbs. Minutes after the ammunition dump went up in flames, Serb soldiers sent several mortar rounds into Sarajevo. After the raid, U.N. officials presented Serb leader Radovan Karadzic with another ultimatum: stop the shelling and give the weapons back by tomorrow, or face another bombing. Karadzic did not immediately respond.