(Adds background) BAGHDAD, May 31 (Reuters) - The U.S. military reported three more deaths in Iraq on Thursday, taking the death toll to 122 for May, already the worst month for U.S. forces there in more than two years. May is the third-worst month overall in the campaign for U.S. soldiers, behind November 2004, when 137 soldiers died, and April 2004, when 135 were killed. A total of 3,473 U.S. soldiers have been killed since the start of the invasion in March 2003. In the latest deaths, two soldiers were killed by a roadside bomb on Wednesday in southwestern Baghdad, the military said in a statement. Two more were wounded. Another soldier wounded by a roadside bomb in Baghdad's northwest on Monday died of his wounds on Tuesday. The U.S. military said another eight soldiers were wounded in a suicide car bomb attack at a checkpoint in the Sunni Arab enclave of Adamiya in northern Baghdad on Wednesday. Three Iraqi civilians, including a child, were also wounded. The U.S. military has said it expects to suffer greater casualties while it pours thousands of extra troops into Baghdad and other areas as part of a major security crackdown aimed at averting all-out sectarian civil war. Most U.S. soldiers are killed by roadside bombs. The U.S. military has accused Iran of supplying particularly dangerous bombs called explosively formed penetrators, which can destroy an Abrams battle tank, to Shi'ite militias.
