At least one U.S. soldier killed in c.Iraq NEAR IMAM AIYUB, Iraq, March 31 (Reuters) - At least one U.S. soldier was killed on Monday in a clash with Iraqi forces armed with rocket propelled grenades about 110 km (70 miles) south of Baghdad. A U.S. officer said that at least one soldier died in the fighting near the town of Imam Aiyub, south of the city of Hilla. U.S. forces were firing artillery towards the town and Iraqi forces were hitting back with mortars and rocket propelled grenades, said Reuters correspondent Andrew Gray, who was travelling with the troops.