KANDAHAR, Afghanistan, Dec. 30 (Xinhua) -- The Afghan troops and the U.S.-led coalition forces have killed nine Taliban militants on a joint operation in the country's south, a police official said on Tuesday.

    The Taliban attacked a convoy of Afghan troops in Nawa district of Helmand province on Monday evening, sparking a three-hour clash, according to Assadullah Sherzad, the police chief of the province.

    "Nine Taliban were killed and their bodies were left in the area. We had no casualties," he said.

    Taliban spokesman Qari Yousef Ahmadi denied the casualty report, saying that only two Taliban militants were killed and three wounded in the gun battle.

    Southern Afghanistan is the center of a Taliban-led insurgency and the world's largest opium-producing area. Taliban militants fighting Afghan and the international troops often conduct such attacks in southern provinces.

    Spiraling conflicts and Taliban-linked insurgency have claimed more than 5,000 people so far this year. On Saturday night, a rare rocket attack fell on Kabul, killing three teenage sisters.