An explosives-rigged minivan crashed into a convoy of Marines that US officials said also came under fire from gunmen. As many as 10 people were killed and 34 wounded as the convoy made a frenzied escape, and injured Afghans said the Americans fired on civilian cars and pedestrians as they sped away. US officials said militant gunfire may have killed or injured civilians, but Afghanistan's Interior Ministry and wounded Afghans said most of the bullets were American. Hundreds of angry Afghans protested near the blast site, denouncing the US presence here. As the Americans fled, they treated every car and person along the busy, tree-lined highway as a potential attacker, said Muhammad Khan Katawazi, the district chief of Shinwar in eastern Afghanistan's Nangarhar province.