Bomb kills five NATO troops in southern Afghanistan

Five NATO soldiers were killed in a bomb attack in southern Afghanistan on Thursday, less than a week after 38 U.S. and Afghan troops died when the Taliban shot down a helicopter.

A spokesman for the U.S.-led International Security Assistance Force (ISAF) declined to elaborate on the circumstances of Thursday's attack except to say it involved a single improvised explosive device, the BBC reported.

It is unusual for a single home-made bomb to kill so many foreign soldiers, most of whom wear body armor which protects vital organs from shrapnel.

At least 387 coalition soldiers have been killed in Afghanistan this year, according to an AFP tally based on figures provided by icasualties.org. More than 50 have been killed in August alone, the BBC reported.

U.S. forces suffered their worst single loss of life in Afghanistan on Saturday when 30 soldiers including elite Navy SEALS were killed in a helicopter crash.

ISAF said Wednesday that the militants responsible for downing the Chinook helicopter were killed in a precision airstrike in Afghanistan's central Wardak province, GlobalPost reported earlier.

The strike also killed a Taliban leader named Mullah Mohibullah, as well as the insurgent that fired the suspected rocket that took down the chopper on Aug. 6.

The BBC said this month's spike in coalition deaths comes as foreign forces begin to hand over security duties to the Afghan military, a key step to the eventual withdrawal of coalition troops.

Southern Afghanistan is the heartland of the Taliban and has seen the worst of the fighting since the 2001 US-led invasion which drove the radical Islamist militia from power.

The Pentagon says 3,485 IEDs exploded or were found in Afghanistan from April to June of this year, a 14 percent increase over the same time last year, according to AFP.