A policeman and another official were knifed to death in the restive far western Chinese region of Xinjiang while investigating an unspecified case, state news agency Xinhua said on Friday. The oil-rich area, which borders Pakistan and Afghanistan, was hit with three separate attacks on government posts before and during the Beijing Olympics that authorities blamed on separatists seeking to disrupt the Games. Xinhua did not give a motive for the attack, which occurred in Jiashi county. The policeman and other official, who was not identified, “were suddenly attacked from behind with knives by several criminal suspects hiding in a pile of corn,” the report said. Five others were wounded and police were still looking for the suspects, it added. The exiled Europe-based World Uyghur Congress said on Thursday local people had reported gunfire during the incident, which happened late on Wednesday. Beijing regularly accuses extremists in Xinjiang of seeking a separate state of East Turkestan.