FACTBOX: Security developments in Iraq, April 20

(Reuters) - Following are security developments in Iraq at 1630 GMT on Sunday.

* Indicates a new or update item.

* BAGHDAD - U.S. forces said they killed six fighters in two separate helicopter strikes overnight in Sadr City. They said they also killed 11 fighters in gunbattles and three died trying to plant a bomb in the area. A U.S. military spokesman called it the "hottest night" for weeks.

* BAGHDAD - Two people were killed and 14 others wounded when two mortar rounds struck the Shi'ite Kadhimiya district of northern Baghdad, police said. One of the mortars hit the Kadhimiya soccer stadium. Police said six people were killed and 22 wounded in the district.

* SINJAR - Police said they had found the bodies of a local council member and his brother after they were abducted from their house in the town of Sinjar, northwest of Mosul, on Saturday.

* SINJAR - Gunmen blew up the main power station in Sinjar overnight causing a power cut off in the town and surrounding areas, police said.

* DIWANIYA - At least two people were killed and five wounded when a roadside bomb exploded near their minibus in Diwaniya, 180 km (112 miles) south of Baghdad, police said.

MUQDADIYA - Iraqi soldiers and police discovered 30 decomposed bodies in a mass grave near the town of Muqdadiya, 90 km (55 miles) northeast of Baghdad, the Iraqi military said.

* BAQUBA - Nine university students and two drivers were kidnapped near Baquba when gunmen stopped their vehicles at a fake checkpoint, police said. Police later said they had freed seven of the students, but the kidnappers escaped with the other hostages.

BAQUBA - Gunmen opened fire at a car, killing an off-duty policeman and the driver in a town near Baquba, 65 km (40 miles) north of Baghdad, police said.

BAGHDAD - The body of one man was found in Baghdad on Saturday, police said.

RASHAD - The bodies of two contractors working with neighborhood security units were found in the town of Rashad, 30 km (20 miles) south of Kirkuk, police said.

BAGHDAD - Seven people were wounded when a Katyusha rocket landed in the Abu Dsheer neighborhood in southern Baghdad, police said.

(Compiled by Aseel Kami and Wathiq Ibrahim; editing by Dean Yates and Peter Graff)