Special report: Tension escalates in Iraq

A pool of blood covers the ground as Iraqis inspect the scene of a car bomb blast in central Baghdad on Wednesday. Baghdad has been battered by a string of deadly mortar and bomb attacks that have killed at least 12 people as Iraq's warring factions battled for control of a shattered country.(Xinhua/AFP Photo) Photo Gallery >>>

    BAGHDAD, Nov. 2 (Xinhua) -- Four Iraqi policemen were killed and five others wounded in two attacks on Thursday morning, an Iraqi Interior Ministry source said.

    Unknown gunmen opened fire from their machine-guns at about 7:00 a.m. (0400 GMT) on a police patrol in the Industrial Street in the Elwiyah neighborhood, the source told Xinhua on condition of anonymity.

    Three policemen were killed and another was wounded in the attack, the source added.

    In a separate incident, the U.S. troops opened fire at 7:30 a.m.(0430 GMT) on policemen affiliated to the Facilities Protection Force who was guarding an under construction building in eastern Baghdad, the source said.

    One policeman was killed and four others were wounded, he said, adding that it was not known why the U.S. troops fired on the guards.

    The U.S. military did not confirm the incident at the time being.

A scene of a car bomb blast on a bridge across Tigris in central Baghdad, Nov. 1, 2006. Baghdad has been battered by a string of deadly mortar and bomb attacks that have killed at least 12 people as Iraq's warring factions battled for control of a shattered country.(Xinhua/AFP Photo) Photo Gallery >>>