An Afghan policeman poisoned seven of his fellow officers and then shot them dead in the southern city of Lashkargah, the governor\'s spokesman, Daud Ahmadi, said on Tuesday. The killings took place on Monday, Ahmadi said, adding that after the killings, the policeman stole the dead men\'s weapons and ammunition, got into a police vehicle, a Ford Ranger, and headed for the Taliban. Taliban spokesman Kari Yusuf Ahmadi said that the policeman was a Taliban militant specially installed in the Afghan police forces. Lashkargah in the Helmand Province is one of seven areas where foreign troops are to transfer security responsibility to their Afghan counterparts this week. NATO officials claimed gains in southern provinces in the past year, but insurgent attacks have increased in recent weeks. Last week, President Hamid Karzai\'s half-brother, a southern political leader, was shot dead by one of his bodyguards.