Attack kills six foreign troops in Afghanistan

The latest deaths come near the end of the bloodiest year for foreign troops and ordinary Afghans since the Taliban were overthrown in late 2001.

ISAF did not give any further details about the attack, including the nationality of those killed, but it was the deadliest insurgent attack on the battlefield since six foreign troops were killed in a suicide attack in Kabul in May.

On November 29, six NATO troops were shot dead by a man wearing an Afghan border police uniform during a training exercise in the east, the worst apparent "rogue" shooting in more than a year.

More than 690 foreign troops have been killed in 2010, by far the bloodiest year of the war.

A total of 521 foreign troops were killed in 2009 and more than 2,260 have died since the beginning of the war. June was the bloodiest month for foreign forces in Afghanistan, with 103 deaths.

The rise in troop deaths will weigh heavily on U.S. President Barack Obama and his administration, who are under increasing pressure to find an end to a war that has dragged on for more than nine years.

NATO leaders agreed at a summit in Lisbon last month to end combat operations and hand security responsibility to Afghan forces by the end of 2014. Obama has promised to begin withdrawing U.S. troops from July 2011.

Critics say the 2014 target set by President Hamid Karzai is too ambitious and point to the shortcomings in Afghanistan's security forces.

(Reporting by Jonathon Burch; Editing by Paul Tait and Alex Richardson)