URUMQI, Aug. 12 (Xinhua) -- Three security staff were killed and another injured on Tuesday morning in an attack at a road checkpoint near Kashi City, northwest China's Xinjiang Uygur Autonomous Region, according to local security authority.

    The attack occurred at about 9 a.m. at the road checkpoint in Yamanya Town of Shule County, according to the county police.

    The number of attacker, who was at large, was not immediately available.

    The four security staff were stabbed by assailant who jumped off from a vehicle passing by the checkpoint.

    The town is about 30 km away from Kashi City, where a raid on border police on Aug. 4 left 16 policemen dead and 16 others injured.

    No evidence has been found suggesting a connection between the two incidents, according to the police. Enditem