The U.S troops killed 18 insurgents in fierce clashes in the restive city of Ramadi, west of Iraq, the U.S. military said on Friday.

The clashes broke out Thursday night when insurgents opened fire on the U.S. troops from several positions in the city, some 110 km west of Baghdad, the military said in a statement.

The U.S. troops fired back with machine-guns, tank fire and air strike, killing 15 insurgents, the statement said.

The troops were under attack again on Friday when insurgents armed with rocket-propelled grenades and small arms opened fire from several buildings, prompting the U.S. troops to fire back and call in another air strike, killing three more insurgents, it said, adding no U.S. troops were killed or wounded in either attack.

Ramadi is the capital of the volatile Anbar province and has been a bastion of insurgency against the U.S. troops since the war began in 2003.

Source: Xinhua