FACTBOX-Security developments in Iraq, April 10

April 10 (Reuters) - Following are security developments in Iraq at 1800 GMT on Thursday.

* Denotes updated or new item.

*Iraqi soldiers discovered 33 bodies in a mass grave at a house in Mahmudiyah south of Baghdad, the U.S. military said. It said initial reports indicated the remains had been buried for more than a year. A number of mass graves have been uncovered in Iraq in recent months in the wake of rampant sectarian fighting in 2006-2007.

BAGHDAD - Six people were killed and 10 wounded in air strikes on Thursday in Sadr City, Iraqi police said. The U.S. military confirmed strikes, but said it was unaware of any deaths.

MOSUL - Three mortar rounds landed on a residential area in southern Mosul, 390 km (240 miles) north of Baghdad, wounding 12 people including an Iraqi soldier, police said.

MOSUL - A bomb exploded in western Mosul, wounding 3 people, police said.

NUMANIYA - A joint U.S.-Iraqi force arrested 15 men during a search and raid operation in the town of Numaniya, 120 km (70 miles) south of Baghdad, and raided a Sadr office in the town, seizing a number of light weapons, police said. They imposed a curfew in the town untill further notice. The U.S. military could not immediately confirm the raid.

BAGHDAD - A roadside bomb targeted a police patrol, killing one civilian and wounding four, including two policemen, in central Baghdad, police said.

BAGHDAD - A roadside bomb wounded six people, including three policemen, on patrol near al-Shaab National Stadium in central Baghdad, police said.

BAGHDAD - A U.S. soldier was killed by an improvised explosive device in central Baghdad on Wednesday, the U.S. military said on Thursday, taking the U.S. death toll for April to 20.

BAGHDAD - U.S. soldiers manning a checkpoint in Sadr City, eastern Baghdad, with Iraqi police killed one person on Wednesday when they were attacked by small-arms fire, the U.S. military said.

BAGHDAD - U.S. soldiers killed four people in northwestern Baghdad late on Wednesday when they responded to an attack with rocket-propelled grenades at a checkpoint, the U.S. military said.

BAGHDAD - A U.S. helicopter fired two Hellfire missiles, killing four people who had attacked U.S. soldiers late on Wednesday at a security station in Sadr City, the U.S. military said.

BAGHDAD - U.S. soldiers killed four people in two different locations in northwestern Baghdad after they were attacked with small-arms fire late on Wednesday, the U.S. military said.

NEAR KIRKUK - In the town of Hawija near Kirkuk, 250 km (155 miles) north of Baghdad, gunmen wearing army uniforms attacked a house, killing two boys and wounding the mother and father.

BAGHDAD - A U.S. fighting vehicle took a rocket-propelled grenade round in northwestern Baghdad on Wednesday night, wounding one U.S. soldier, the U.S. military said.

BAGHDAD - A U.S. vehicle in Sadr City, eastern Baghdad, was struck by an improvised explosive device on Wednesday night and one U.S. soldier was wounded, the U.S. military said. (Edited by Noah Barkin)