6 slain troops in Afghanistan all Americans

KABUL, Afghanistan - A U.S. official says six service members slain by an Afghan police officer were all Americans.

The U.S. official spoke on condition of anonymity because next of kin had not been notified.

NATO and Afghan officials say the border policeman turned his weapon on six of his NATO counterparts Monday during a training mission. It was the latest in a string of such killings this year as U.S.-led troops intensify a push to expand Afghan forces. The Taliban claimed responsibility for the attack.