Afghan officials say "hundreds" of Afghan soldiers have been arrested or expelled from the army as officials crack down on a rising number of attacks on NATO-led troops by members of the Afghan security forces.
Defense Ministry spokesman General Zahir Azimi told a news conference that the attacks were "a matter of concern" for the Afghan government.
Meanwhile, NATO announced that Secretary-General Anders Fogh Rasmussen had shared his "deep concerns" with Afghan President Hamid Karzai about the rising number of attacks on NATO troops by members of the Afghan security forces.
NATO spokeswoman Carmen Romero said that during a telephone conversation, Rasmussen outlined measures taken by NATO to reduce the number of attacks.
The spokeswoman said Karzai assured the secretary-general that he is also doing all he can to prevent further "insider" attacks.
On September 2, the U.S. military announced that its special forces had suspended training for about 1,000 Afghan police recruits in order to investigate existing security force members.
Members of the Afghan security forces have opened fire on their Western allies more than 30 times so far this year, killing at least 45 foreign troops.
Taliban insurgents claimed responsibility for many of the attacks, saying their fighters have infiltrated the army and police.
Based on reporting by Reuters, AFP, and AP