BAGHDAD — Four rockets struck an army base near Baghdad International Airport on Monday, wounding at least six Iraqi personnel. It is the latest attack on military installations hosting U.S. forces.

The rockets were fired from an adjacent neighborhood and hit a barracks for Iraq’s elite counterterrorism forces early Monday, according to a military official at the airport. He spoke on the condition of anonymity because he was not authorized to talk to the media.

Iraq’s Joint Operations Command said in a statement that six “fighters” had been injured and that the launch site had been located. Two counterterrorism force members were critically wounded, the military official at the airport said.

The barrage Monday follows similar rocket attacks on military bases in northern and western Iraq last week. U.S. troops were present at all three sites as part of the coalition against the Islamic State militant group, a mission that included training and partnering with Iraqi forces.

On Thursday, several rockets hit the Balad air base, which hosts U.S. troops and government contractors and is about 50 miles north of Baghdad. There were no injuries or damage to facilities. Two days earlier, at least five rockets were fired at Ain al-Asad air base in Anbar province.

No group has asserted responsibility for the attacks. But U.S. officials have said that they believe Iran-backed militias are behind the assaults.