BAGHDAD, Iraq (CNN) -- Iraqi police said they killed an al Qaeda in Iraq leader on Saturday in the northern city of Samarra, a day after five U.S. soldiers were killed in two explosions elsewhere.
Mahmoud al-Douri, who also went by the name Abu Omar, was killed during a raid on a Samarra house, a police official said. Police said al-Douri shot at them and they fired back, killing him.
Weapons, explosives and a car bomb were found at the house, the Samarra police official said.
Samarra is in Salaheddin province, one of four northern Iraq provinces where Iraqi and U.S. forces have been conducting a stepped-up campaign against militants.
Four of the five U.S. soldiers who died Friday were killed when their vehicle struck a roadside bomb during a combat patrol northwest of Baghdad, according to a U.S. military statement.
The fifth was killed by an explosion near the soldier's vehicle in Tameem province, north of Salaheddin province. Three other soldiers were wounded.
The military was withholding the names of the five soldiers who died until their families are notified.
Since the start of the war, 3,951 U.S. troops have died in Iraq -- 14 in February. Seven Defense Department contractors also have been killed.
A roadside bomb killed an Iraqi civilian and wounded four others Saturday morning in Nahrwan, a mostly Shiite district in southeastern Baghdad, an Iraqi Interior Ministry official said.
The bodies of 12 people believed to be victims of al Qaeda in Iraq were found in a mass grave near Baquba on Saturday morning, according to an official with the Diyala province operations command.
Three women were among the dead, the official said. E-mail to a friend
CNN's Jomana Karadsheh contributed to this report.