A rogue Afghan soldier attacked a group of British troops in the province of Helmand, southern Afghanistan, killing three and wounding four others before escaping.The Taliban claimed that the attacker was a militant sympathiser who was taken in by insurgents after the assault, one which could further weaken support in Britain for an unpopular war that has now taken the lives of 317 Britons. The motive for the attack in the Nahr-e-Sarraj district remained unclear, but it could prove deeply embarrassing for the Afghan government and US military leaders, who have stressed the importance of ratcheting up the training of Afghan security forces to gradually take on more responsibility for securing their own country. British Defense Minister Liam Fox said training Afghan security forces would continue because it is vital to the international security mission in Afghanistan, and today's events will not undermine the real progress we continue to make. British Prime Minister David Cameron has said he wants the country's 10,000 troops out by the time of Britain's next election, which must be held by 2015.