An Afghan army soldier opened fire on troops from the US-led coalition operating in northern Afghanistan Friday, killing two and wounding one before killing himself, the US and Afghan militaries said. A joint statement from the forces did not announce the nationalities of the foreign casualties, leaving this to their home nation, or say exactly where in the north the incident occurred.

"One coalition service member was killed today, another died of wounds, and a third was wounded by an Afghan National Army soldier who reportedly fired upon them," the statement said. The Afghan soldier killed himself immediately after the incident, it said.

Most of the troops in the coalition are from the United States, which has 38,000 troops in Afghanistan helping to fight extremist Islamist militants from the Taliban and other radical outfits. The US military is at the forefront of efforts to build the Afghan security forces so they can tackle the extremist threat themselves.

The statement quoted the Afghan Defence Minister, Abdul Rahim Wardak, expressing his sorrow about the incident, which is under investigation. "It is too early to speculate, but the investigation will bear out the truth," the minister was cited as saying, adding that "full corrective action will be taken."

Copyright Agence France-Presse, 2009