Special report: Tension escalates in Iraq

    BAGHDAD, April 23 (Xinhua) -- The U.S. military said Wednesday that its forces killed 15 gunmen overnight in Shiite areas in Baghdad, which witnessed fierce fighting recently between Shiite Sadr followers and the U.S.-backed Iraqi security forces.

    A U.S. patrol was attacked by gunmen in eastern Baghdad with a roadside bomb and rocket propelled grenades. The soldiers fired back with small arms fire, killing six gunmen, a military statement said.

    A U.S. unmanned drone spotted two gunmen putting a mortar tube into a vehicle and then drove off in northeastern Baghdad. The drone then fired a Hellfire missile, killing two gunmen, the statement said.

    In a separate incident, U.S. soldiers were attacked by two teams of gunmen with rocket propelled grenades in eastern Baghdad, prompting the soldiers to return fire, killing five gunmen, it said.

    In addition, soldiers opened fire to a militant who was spotted planting a roadside bomb in northeastern the capital and killed him, it added.

    Also in the area, the soldiers killed another gunmen after coming under small arms fire, the military said.

    The areas where the incidents took place are strongholds of the Shiite Mahdi Army militia loyal to cleric Muqtada al-Sadr who threatened on Saturday of an "open war" against the Iraqi government if the U.S.-backed Iraqi troops continue to crack down on his Mahdi Army militiamen.