Witnesses say the protesters gathered Sunday to demonstrate against forced relocation from their homes, prompted by the construction of a major hydroelectric dam. They say security forces converged on the protesters and opened fire.
There is no word on the condition of those reported hit by gunfire. Witnesses say security forces took them away from the scene.
There is no Chinese confirmation of the reported incident in Sichuan's Tawu County.
The Tibetan government-in-exile accuses Beijing of trying to force ethnic Tibetans from their ancestral lands in order to extract minerals and other resources from the region.