The Afghan army has detained or sacked hundreds of soldiers for having links to insurgents, the Defence Ministry said on Wednesday, as it tries to stem an alarming number of so-called insider attacks eroding trust between Afghans and their allies.

Ministry spokesman Mohammad Zahir Azimi did not provide any other details or specific numbers on Wednesday. He said many of the troops had been discharged from the military because they had suspect documents, either incomplete or forged.

“Using an army uniform against foreign forces is a serious point of concern not only for the Defence Ministry but for the whole Afghan government,” Azimi said, adding that President Hamid Karzai had ordered Afghan forces to devise ways to stop insider attacks.

On more than 30 occasions so far this year, members of the Afghan security forces have opened fire on their Western allies, killing at least 45 foreign troops — the majority of them American.

Defence ministry spokesman General Zahir Azimi told a news conference on Wednesday that the attacks were “a matter of concern” for the Afghan government.

meanwhile on September 2, the U.S. military announced that its special forces have suspended training for about 1,000 Afghan police recruits in order to investigate existing security force members.