China Daily and Xinhua reported the shooting occurred last Sunday in Aba County in Sichuan province, one of the areas where the protests have spread. The report said four protesters were wounded.

The protests began in the Tibetan capital of Lhasa last Friday, marking the anniversary of the 1959 failed Tibetan rebellion against Chinese rule. Until now, China has blamed the violence on supporters of the Dalai Lama, the Tibetan spiritual leader living in exile in India since 1959.

Police in the Tibetan-inhabited Aba fired on and wounded four rioters "in self-defense" during Sunday's unrest, Xinhua quoted police sources as saying.

The report said the rioters had set fire to a police station and attacked police with knives and tried to take away their weapons. The report said police fired warning shots, but the rioters continued attacking officers.

The injured attackers later ran away with other rioters, who had destroyed 15 police vehicle, the report said. They were being sought.

Authorities in Lhasa have issued arrest warrants for 24 people, accused of being involved in last Friday's incidents, the report said.