A U.S. soldier and at least six Iraqis were killed in Baghdad and north of the Iraqi capital Saturday in a spate of roadside bombings, officials said. Security forces searched for a private German plane missing in northern Iraq. An Iraqi police major was assassinated by drive-by gunmen in the insurgent stronghold of Ramadi, west of Baghdad, in the latest attack targeting security forces that the United States hopes will eventually take control of Iraq. The U.S. military said a roadside bomb struck an American vehicle at about 8 a.m. in eastern Baghdad, killing a soldier assigned to the Multi-National Division-Baghdad, according to a report of the Associated Press.