BAGHDAD (Reuters) - U.S. military helicopters fired on suspected militia fighters in southern Iraq on Wednesday, killing one, in a rare American air strike responding to a rocket attack on an airport, the U.S. military said.
The U.S. response at Basra came at a sensitive time as Baghdad and Washington debate whether American soldiers need to stay past a planned withdrawal at the end of 2011 after they finished combat missions last year.
Basra, the strategic oil hub for the OPEC member country, has been relatively calm in recent years compared to the more restive northern and central parts of the country, where al-Qaeda affiliates are still more active.
The U.S. helicopter intervention came after seven rockets were fired at U.S. and Iraqi forces stationed at Basra airport.
"The helicopter team was airborne while conducting a routine mission when they received the report about the base attack," the U.S. military said in a statement.
"They viewed two males actively loading and launching the rockets and requested permission to engage."
After the U.S. strike, "a team of Iraqi security forces were alerted and dispatched to the site and found three of the men responsible for the attack -- one dead and two wounded," the U.S. military said.
Local Iraqi media reported a civilian was killed and three others wounded in the U.S. operation, and the U.S. military said it was investigating whether there had been civilian casualties.
U.S. troops ended combat missions in August, and the remaining U.S. forces are mainly engaged in advisory and training roles. But they retain the right to defend themselves.
Eight years after the U.S. invasion that toppled Saddam Hussein, violence in Iraq has fallen since a peak of sectarian conflict, but Sunni Islamist insurgents linked to al-Qaeda and Shi'ite militias continue daily bombings and assassinations.
U.S. officials say attacks have increased, especially in the south, where militias are trying to take credit for appearing to have forced the U.S. military to leave the country.
A senior Iraqi security official, who asked not to be identified because of the sensitivity of the matter, said U.S. forces in Basra had grown frustrated with the Iraqi military response to recent attacks on their base.
"During recent meetings with the Americans, they were complaining our security forces are not doing enough to stop bomb and rocket attacks targeting their base and ground troops," the security official said.
Iraqi Prime Minister Nuri al-Maliki says local forces are ready to contain any internal threat, but acknowledges gaps in air, naval and intelligence capabilities. U.S. officials say Maliki needs to ask soon if any troops are to stay.
(Reporting by Patrick Markey in Baghdad and Aref Mohammed in Basra)