WASHINGTON - The United States has stopped training Afghan forces due to rising incidents of the so-called insider attacks in Afghanistan, The Washington Post reported Sunday.The newspaper said that the commander of the US special forces has suspended training for all new Afghan recruits until Afghan soldiers are reinvestigated for their possible ties to Taliban militants.The Post says the revetting process will affect more than 27,000 Afghan troops.“We have a very good vetting process,” the paper quoted an unnamed senior special operations official as saying.“What we learned is that you just can’t take it for granted. We probably should have had a mechanism to follow up with recruits from the beginning.”Afghan forces have killed at least 45 foreign forces, mostly US soldiers, in such attacks so far in 2012.On August 29, an Afghan soldier opened fire on a group of Australian troops in the southern district of Tarin Kowt, killing three of them.Earlier in August, six US soldiers were killed in a series of such attacks in a single day.US Defence Secretary Leon Panetta has expressed deep concern about the rise in the insider attacks. AFP from Kabul adds: There has been a sharp rise in so-called ‘green-on-blue’ attacks recently, in which members of the Afghan security forces turn their weapons on their Western allies, sometimes their military trainers.There have been more than 30 such incidents this year, claiming the lives of 45 coalition troops - about 14 per cent of the overall death toll in the war for 2012.“Current partnered operations have and will continue, even as we temporarily suspend training of about 1,000 new ALP (Afghan Local Police) recruits while revetting current members,” a spokesman for the US forces in Afghanistan, Colonel Thomas Collins, said.The ALP is a US-sponsored police force with around 30,000 members, recruited to fight Taliban insurgents in remote areas of the Afghan countryside.“While we have full trust and confidence in our Afghan partners, we believe this is a necessary step to validate our vetting process and ensure the quality indicative of Afghan Local Police,” the spokesman said.The Washington Post said the re-vetting process would affect more than 27,000 Afghan troops. The suspension was temporary, the colonel said but gave no timeframe.The US-led Nato troops will withdraw at the end of 2014, giving all security responsibilities to the Afghan forces in a US-designed programme which began earlier this year.According to the Post, numerous military guidelines were not followed by either Afghans or Americans because of concerns that they might slow the growth of the Afghan army and police.The Taliban have stepped up their attacks in recent months as part of efforts by the insurgency to undermine the transition process.