The temporary training freeze will affect some 1,000 new police recruits, while the NATO-led International Security Assistance Force (ISAF) investigates Afghan troops for links to the Taliban-led insurgency.

According to the US daily The Washington Post, some 27,000 current members of the Afghan security forces are being re-vetted for links to the insurgency.

The training halt will mostly affect the Afghan Local Police (ALP), a 30,000-strong police force sponsored by the US that fights the Taliban in the remote areas of the Afghan countryside.

"We have temporarily suspended all new Afghan recruits until Afghan soldiers are investigated for ties with the insurgents," ISAF spokesman James Graybeal said. "We are concerned about insider attacks and we are in the process of vetting Afghan troops."

"It is an attempt by ISAF and our Afghan partners to reduce the number of insider threats," Graybeal added.

Insider attacks

The training suspension comes after a string of attacks by numerous Afghans in uniform against their erstwhile NATO allies. At least 45 coalition troops have been killed in such "green-on-blue" attacks in 2012 alone.

Some 130,000 NATO-led ISAF troops are currently serving in Afghanistan. Most of them are scheduled to withdraw from the country by 2014, a deadline set by US President Barack Obama.

The training of local security forces is key to the withdrawal timetable, which assumes Afghan troops and police will be able to take over responsibility for the country's security.

slk/tj (AFP, DAPD, dpa)