Kabul , Afghanistan ( CNN ) The Afghan Taliban have claimed responsibility for a suicide attack that killed 3 American contractors at a military base attached to the Kabul airport . The attacker in the Thursday incident was a Taliban agent who `` had penetrated into the security forces and was waiting for such a target for a long time , '' a spokesman for the group , Zabiullah Mujahid , said Friday . `` Yesterday in the evening he managed to get to a crowd of invading and infidel American military forces where he turned his gun towards them and opened fire , '' he added . `` During the gun battle , Ehsanullah was also killed by the enemy . '' A U.S. military official earlier told CNN the three American were contractors , not active duty forces .
The attacker is also killed . The Americans were contractors .