US troops have questioned hundreds of people and detained 11 in the search for three American soldiers feared captured by al-Qaida during a deadly weekend ambush south of Baghdad, the military said Tuesday. Four American soldiers and an Iraqi were killed and their vehicles burned in the weekend ambush. Two Defense Department officials said they could not yet identify one of the dead, hampering the military's ability to determine who was missing. The officials spoke on condition of anonymity because the families had not yet been notified. "We have conducted more than 450 tactical interviews and detained 11 individuals" as of Monday night, US military spokesman Lt. Col. Christopher Garver said. Garver said the Americans were also turning to the local population, which he said "continues to be helpful in providing tips."