6 U.K. troops feared dead in Afghan blast (CBS/AP) LONDON - Britain's Ministry of Defense says six service members are missing and presumed dead after an explosion hit their vehicle in southern Afghanistan. A massive explosion hit the heavily armored troop carrier, which was on patrol in Helmand province Tuesday evening, according to the BBC. It was unclear whether the explosion was caused by an improvised explosive device (IED), or roadside bomb - the weapon of choice for Taliban militants targeting Western troops - or if the British vehicle hit an old Soviet-era landmine in the road. U.S. talks with Taliban unsettle the streets of Kabul Koran-burning probe finds 5 U.S. troops involved Conflicting accounts over Afghan Koran burnings Weather was hampering the search for the missing soldiers, no bodies have been recovered. So far this year, 54 NATO troops have been killed in Afghanistan, including 38 from the United States and four from Britain. This would be the biggest single loss of life of British troops since 2006 when 14 troops were killed. If the six troops were killed, the total death toll for British troops in Afghanistan will rise above 400, according to the BBC. The families of the soldiers have been informed.