American warplanes bombed military communications sites in southern Iraq Saturday after the Iraqis fired anti-aircraft guns at U.S. planes, U.S. Central Command said.

Around 2:45 p.m. EST, the U.S. planes bombed six cable relay sites between Al Kut, about 95 miles southeast of Baghdad, and Basra, about 245 miles southeast of Baghdad, Central Command said in a statement.

The airstrikes came after Iraqis fired anti-aircraft artillery at U.S. warplanes patrolling the no-fly zone over southern Iraq, the statement said.

The United States and its allies set up no-fly zones over southern and northern Iraq after the 1991 Persian Gulf War to keep Saddam Hussein's military from attacking opposition Kurdish and Shiite Muslim groups. Iraq says the zones are illegal and frequently tries to shoot down the planes patrolling them, though it has never downed a piloted plane in a no-fly zone.

The Iraqis have fired on southern no-fly zone patrols more than 100 times so far this year and sent aircraft into the zone three times, the Central Command statement said. The United States has responded with more than 40 airstrikes.