Five Afghan police shot dead seven fellow officers as they slept, before defecting to join Taliban guerrillas fighting in southern Afghanistan, a provincial official said on Monday. Sunday night's incident outside Qalat, the provincial capital of southern province of Zabul, comes amid the bloodiest period in an insurgency raging since US-backed forces toppled the militants' government in 2001. "The seven policemen were asleep when the other five jumped, killed them, took their arms and joined the Taliban," provincial spokesman, Gulab Shah Alikhail, said. He said provincial officials were hunting the five policemen and had "intelligence" that they had joined the Taliban.