Three US soldiers were killed in a bridge collapse caused by a bomb blast near Baghdad on Sunday, the military said, bringing the total US military death toll in Iraq to more than 3,500.

"Three coalition force soldiers were killed and six were wounded when the checkpoint they were manning was struck by a suicide car bomb south of Baghdad near Mahmudiyah June 10," the military said in a statement on Monday.

An interpreter was also wounded in the attack, which destroyed part of a highway overpass, it said.

The deaths bring to 28 the number of US troops killed in Iraq so far this month and the overall death toll to at least 3,501 since the March 2003 invasion, according to an AFP count based on Pentagon figures.