An Afghan wearing a uniform killed three US soldiers in the southern province of Helmand, a spokeswoman for NATO-led forces in Afghanistan said.
Afghan officials said the three men were all special forces members and were killed while attending a meeting in Sangin District late yesterday.
So-called ''green on blue'' shootings, in which Afghan police or soldiers turn their guns on their Western mentors, have seriously eroded trust between the allies.
NATO combat soldiers are preparing to hand over to Afghan forces by 2014, after which most foreign forces will leave the country.
According to NATO, there have been 24 such attacks on foreign troops since January in which 28 people have been killed. Last year, there were 21 attacks in which 35 people were killed.
In a grim 24 hours for the NATO-led force, three US soldiers and a US aid worker were killed earlier yesterday in the eastern province of Kunar in an attack by a suicide bomber.
