U.S. in big battles with Shi'ite gunmen in Baghdad

By Peter Graff and Tim Cocks

BAGHDAD (Reuters) - U.S. forces killed 45 Shi'ite militiamen in Baghdad in fierce fighting that included a tank battle with dozens of gunmen who attacked a checkpoint under cover of a dust storm, military officials said on Monday.

Four U.S. soldiers were also killed in rocket or mortar attacks in the Iraqi capital on Monday, the military said.

The U.S. military said the checkpoint attack on Sunday night sparked the biggest battle in the city since Prime Minister Nuri al-Maliki cracked down on militias a month ago.

It said 22 gunmen died in the assault. Another 23 were killed in other battles since Sunday in and around the eastern Baghdad slum district of Sadr City, stronghold of anti-American Shi'ite cleric Moqtada al-Sadr.

The fighting showed some members of the cleric's Mehdi Army militia have apparently defied his order to observe a truce, raising questions about how much he controls his followers.

U.S. and Iraqi troops have been locked in a month of fighting with militiamen since Maliki, himself a Shi'ite, ordered the offensive in the southern oil city of Basra.

They have taken over about a quarter of Baghdad's Sadr City where Sadr's fighters held sway.

The Sunday attack was accompanied by multiple rocket attacks on the Green Zone government and diplomatic compound in central Baghdad. Militants fired more rockets and mortars on Monday. Among the casualties were three U.S. soldiers who were killed in eastern Baghdad and one soldier in the city's west, the military said. It gave no further details.