(Adds tape of execution of Iraqi policemen) By Mussab Al-Khairalla BAGHDAD, March 3 (Reuters) - U.S. air strikes in and around Baghdad killed senior insurgents suspected of targeting American helicopters and seven members of what the U.S. military said on Saturday was an al Qaeda cell responsible for car bombings. In the restive western Anbar province, where U.S. forces are battling al Qaeda and other militants, a suicide car bomb killed 12 people at a police checkpoint in the city of Ramadi. Three U.S. soldiers were killed by a roadside bomb that hit their vehicle in central Baghdad where U.S. and Iraqi forces are implementing a major security crackdown regarded as a last ditch effort to stop Iraq tearing itself apart through a civil war. The U.S. military said an air strike on Friday north of Baghdad near the town of Taji, which is home to a major U.S. air base, destroyed weaponry including a vehicle mounted with anti-aircraft artillery. "Coalition forces believe key terrorists were killed during the air strike ... Intelligence reports indicated this network is responsible for threats to coalition aircraft," the military said in a statement, without elaborating. Insurgents have shot down eight helicopters in Iraq since Jan. 20, killing 28 people, mostly soldiers. Six of those helicopters were U.S. military aircraft and two belonged to a private American security firm. U.S. commanders say insurgents appear to be targeting helicopters to undermine the Baghdad security plan that began last month. The U.S. military said another air strike in Arab Jabour in southern Baghdad on Saturday killed seven al Qaeda suspects thought responsible for a large number of suicide car bombings. After being fired on by insurgents on the opposite side of the Tigris river, U.S. forces called in aircraft which dropped two bombs, setting off a secondary explosion the U.S. military said indicated the targeted building contained explosives. A U.S. spokesman said there were no civilian casualties. ANBAR CLASHES In Anbar, Saturday's suicide car bombing killed 12 people including three policemen and one child, according to Lieutenant Colonel Tareq Yussuf. A hospital source also put the death toll at 12, with another 22 people wounded. The Iraqi Defence Ministry said in a statement Iraqi security forces had killed 39 militants in the vast western province on Friday and had detained 30 others. It was unclear if there were any government casualties. Outside the capital, one of the most critical areas of Iraq is Anbar where Sunni tribal leaders have been engaged in an increasingly violent power struggle with al Qaeda. Enlisting the support of Sunni tribes against al Qaeda is regarded by some Iraqi officials as the best hope of pacifying Anbar, which is the most dangerous province for U.S. soldiers in Iraq but also home to vital trade routes to Jordan and Syria. An al Qaeda-linked group posted a video of the execution of a group of 18 policemen it seized in Diyala province on the Internet on Saturday. The footage came a day after the bodies of 14 policemen, all shot in the head, were found north of Baghdad. The video, from the self-style Islamic State in Iraq, showed the men kneeling in a row, their hands tied behind their backs and eyes covered. At least two masked gunmen were shown opening fire on the men from behind with pistols while a third militant stood by, holding the group's flag. In other violence, insurgents killed six members of one Sunni family on Saturday when they stormed a home in the town of Yusufiya, just south of Baghdad, police said. Relatives said insurgents had sent death threats after the family had met local Shi'ite leaders in an attempt at reconciliation. (Additional reporting by Firouz Sedarat in Dubai)
