FACTBOX: Security developments in Iraq, April 12

(Reuters) - Following are security developments in Iraq at 11: 00 a.m. EDT on Saturday.

* BAGHDAD - Four bodies were found in Mahmudiyah, 30 km (20 miles) south of Baghdad, on Saturday, Iraqi Army commander Ali al-Farraji said. He said this brought the total body count from a mass grave uncovered in the area on Thursday to 40. The bodies are believed to have been buried for over a year.

WESTERN IRAQ - Iraqi police captured senior al Qaeda member Ali al-Isawi, also known as Ali Rummana, in Rutba, west of Baghdad near the Syrian border, police Major Sabbar al-Dulaimi said.

BAGHDAD - U.S. and Iraqi forces killed at least 13 gunmen in heavy battles overnight around Baghdad's Sadr City, the U.S. military said on Saturday.

BAGHDAD - A U.S. soldier was killed by an improvised explosive device in northwest Baghdad on Saturday morning, the U.S. military said.

MOSUL - Three bodies of Islamic party office guards were found with gunshot wounds to the body and head in western Mosul, 390 km (240 miles) north of Baghdad, police said.

NEAR MOSUL - A roadside bomb killed one Iraqi soldier when it struck his patrol, west of Mosul, police said.

BAGHDAD - A roadside bomb struck a police patrol, killing one policeman and wounding five others in the Hay Ur district, in northern Baghdad, police said.

BAGHDAD - U.S. forces arrested a suspected Iranian-trained Special Groups weapons facilitator on Saturday during operations northeast of Baghdad, the U.S. military said.

KIRKUK - A roadside bomb wounded one soldier and one member of a U.S.-backed neighborhood patrol unit when they were traveling off-duty in their car in southern Kirkuk, 250 km (155 miles) north of Baghdad, police said.

(compiled by Aws Qusay, editing by Noah Barkin)