KABUL - Seven international soldiers have been killed by their local colleagues in a bloody week of violence in Afghanistan, further eroding trust between foreign troops and the Afghans they work with. Six died on Friday alone - three American soldiers were shot by an Afghan policeman who invited them to a meal and three other troops were killed by an Afghan civilian employed on a Nato base, military and Afghan officials said. Nato has about 130,000 soldiers helping the Afghan government fight an insurgency by Taliban.

, but they are due to pull out in 2014 and are increasingly working with Afghans they are training to take over. Green-on-blue attacks, in which Afghans turn their weapons against their foreign allies, have killed a total of 34 international soldiers this year, according to a Nato count. The seven deaths this week - one soldier was killed on Tuesday - make up around 40 percent of the total of some 17 foreign troops killed. “Clearly as far as the future partnering and training and mentoring of Afghan forces by NATO and the US is concerned, it is going to have a very negative effect and the lack of trust between the two sides is going to grow,” said author and analyst Ahmed Rashid.