Afghanistan blast kills nine Nato troops

Taliban bomb that exploded in field where soldiers were patrolling was worst such attack since October 2009

Nine Nato service members were killed in Afghanistan, including seven US troops who died when a bomb exploded in a field where they were patrolling on foot, officials said.

The Taliban claimed responsibility for the blast. The international military coalition reported that one additional Nato service member was killed when a helicopter crashed in the east of the country.

Thursday's explosion was the worst single attack against Nato forces by one of the Taliban's crude, homemade bombs since October 2009. So far this year, 189 coalition troops have died in Afghanistan.