A car bomb targeting Iranian pilgrims struck this morning near a Shiite shrine in the holy city of Kufa, killing at least 12 people and wounding 37, police said.
The bomb exploded near the shrine of Maitham al-Tamar and yards from the Kufa mosque.
Attacks on houses of worship have stoked tensions between Shiite and Sunni Muslims.
Elsewhere, hundreds of U.S. Marines on Wednesday stormed through the largest hospital in western Iraq, taking control of a facility they said was being used by insurgents.
Al Qaeda in Iraq militants had been using Ramadi General Hospital, a seven-story building with about 250 beds, to treat their wounded and fire on U.S. troops, the Marines said.
They said wounded Iraqi police officers who had been taken to the hospital were later found beheaded.
The Marines from the 3rd Battalion, 8th Marine Regiment said they met with no resistance. They said they found about a dozen triggering devices for roadside bombs hidden above the tiled ceiling of an office.