Six British soldiers were killed and eight others injured in attacks in southern Iraq. In other clashes west of Baghdad, at least three Iraqis were killed and one U.S. soldier was wounded.
British forces came under two separate attacks near the city of Amarah, about 200 kilometers north of Iraq's second largest city, Basra. In one attack a helicopter also came under fire.
It was the first major attack against British troops in Iraq since the fall of the regime of Saddam Hussein in April.
U.S. troops have come under almost daily attacks and ambushes during the past several weeks in areas north and west of Baghdad. The latest attacks against American forces occurred around the towns of Ramadi and Fallujah, west of the capital.
Military officials blame the attacks on armed groups still loyal to Saddam Hussein's ousted regime.
The military has been conducting extensive security sweeps to try to eliminate this armed resistance. Iraqi activists say the fact that Saddam Hussein has not been proved dead or been captured, is an incentive for his loyalists to continue their attacks.
American military officials in Baghdad are not commenting on an operation last week in which U.S. special forces targeted a convoy suspected of carrying senior members of the ousted regime. The operation occurred along the border with neighboring Syria. Several Syrians were injured in a firefight involving U.S. troops.
U.S. defense officials say investigators have not yet determined the identities of those killed in the attack on the convoy. They say they will conduct DNA tests if necessary to try to identify the victims. But they say there is no indication that Saddam Hussein or his two sons are among the dead.