An armed confrontation between two Iraqi army units Friday left one soldier and one civilian dead, raising questions about the U.S.-trained force's capability to maintain control at a time when sectarian and ethnic tensions are running high. On Friday morning, a roadside bomb struck an Iraqi army convoy, which police said was made up of Kurdish soldiers. Four soldiers were killed and three were wounded, police said. US military officials put the casualty figure at one dead and 12 wounded. According to both the US and Iraqi accounts, the wounded were rushed to the US military hospital in Balad. Police said that as the Kurdish soldiers drove to the hospital, they fired weapons to clear the way, and one Iraqi Shiite civilian was killed. Shiite soldiers from another Iraqi unit based in Balad rushed to the scene, and the Kurds decided to take their wounded elsewhere, Iraqi police said. Iraqi troops tried to stop them and shots were fired, killing one Shiite soldier, Iraqi police said.