BAGHDAD, March 22, SPA -- A U.S. air strike struck checkpoints north of Baghdad on Saturday, killing six guards and wounding two, Iraqi police said. Meanwhile, three U.S. soldiers were killed in a roadside bombing, the military said, bringing the American death toll since the war's start five years ago closer to 4,000. Two Iraqi civilians also were killed in the attack northwest of Baghdad, according to a report of the Associated Press.--SPA www.spa.gov.sa/538777