Two NATO soldiers have been killed in Kandahar and a third was wounded when two attackers wearing the uniform of Afghan security forces opened fire on them.

Romanian Defence Ministry officials are reported to have said those killed were members of the Romanian special forces.

The troops were shot while training police in the city of Kandahar. There have been several incidents in recent years of Afghan security forces turning their arms on coalition troops.

However more recently so-called “green-on-blue” insider attacks – usually committed by Taliban members or supporters – have become much less frequent.

The attackers yesterday were killed after carrying out their attack, a Nato statement said, and an investigation is underway.

One Afghan policeman is reported to have been arrested and is being questioned.