6 British troops presumed dead in massive Afghan blast Six British troops were missing and presumed dead after a massive blast destroyed their tank-like armored vehicle in Helmand province, British and coalition military officials said Wednesday. It would be the largest loss of British military lives in a single incident in Afghanistan in nearly three years. About 24 hours after the explosion, which took place Tuesday, the 25-ton Warrior vehicle, which has tracks like a tank, still had not been recovered, British officials said. For that reason, the fatalities were not yet listed as confirmed, but military officials said the soldiers' families had been notified of the presumed deaths. A Helmand provincial spokesman, Daud Ahmadi, said the explosion, believed due to a roadside bomb, had taken place in Helmand's Gereshk district, not far from the country's main ring-road highway. The NATO force also said the blast was from an improvised explosive device, or IED, and confirmed the presumed deaths of six service members without specifying their nationality. Destroying or disabling such a heavy vehicle and killing all those inside would require an extremely powerful bomb, and the incident pointed to a continuing Taliban presence in Helmand province despite military gains touted by NATO's International Security Assistance Force, or ISAF. Helmand, together with neighboring Kandahar province, is considered the Taliban movement's home ground, but the insurgents were driven over the last two years from many longtime strongholds. The deaths came one day after a trip to Helmand by the American commander of the NATO force, Marine Gen. John Allen. During his visit, he told U.S. Marines in Marjah, the scene of a major offensive in February 2010, that their efforts were "helping to make the area a safer place for Afghans to live and work," according to a military news release. Several parts of Helmand, including its capital, Lashkar Gah, are now under the security control of the Afghan police and army -- part of a nationwide push for Afghan forces to take over most combat duties by the end of next year. That coincides with a drawdown of U.S. troops that began in the latter part of last year and is to accelerate this year. By the end of 2012, the U.S. contingent is to be reduced to about 68,000 troops, down from a high of more than 100,000. Americans make up the bulk of the NATO force.