International coalition officials say the insurgents who attacked a British military base in Afghanistan Friday, killing two U.S. Marines, were dressed in U.S. Army uniforms and were armed with automatic rifles, rocket propelled grenade launchers and suicide vests.

The coalition said in a statement Sunday the 15 militants were organized into three teams and “executed a well-coordinated attack” against the airfield on Camp Bastion in Helmand province.

The alliance say the attackers destroyed six Harrier jets and “significantly damaged” two more. The militants also destroyed three coalition refueling stations and damaged six aircraft hangars.

International troops killed 14 of the insurgents and wounded one, who is in custody. Earlier reports said 18 militants died in the attack.

In addition to the two U.S. Marines killed in the assault, eight military members and one civilian contractor were wounded.

The Taliban has claimed responsibility for the attack.

A spokesman for the militant group said Saturday the attack was in response to a film produced in the U.S. that insults the Prophet Muhammad and because Britain's Prince Harry is serving at the base.

Officials say Prince Harry, who is third in line to the British throne, was never in danger. He is deployed at the base as a helicopter pilot. The Taliban has vowed to kill him.