BEIJING — Deadly clashes between ethnic Tibetans and Chinese security forces have spread to a second area in southwestern China, an overseas Tibetan activist group said today.

Two Tibetans were killed and several more were wounded Tuesday when security forces opened fire on a crowd of protesters in Seda county in politically sensitive Ganzi prefecture in Sichuan province, the group Free Tibet said. It quoted local sources as saying the area was under a curfew.

The reported violence comes as some 30 Tibetans who were wounded Monday when Chinese police fired into a crowd of protesters were sheltering in a monastery in neighboring Luhuo county, a Tibetan monk said. Military forces have surrounded the building, said the monk, who would not give his name out of fear of government retaliation.

The counties have been tense for some time, and at least 16 Buddhist monks, nuns and other Tibetans have set themselves on fire in protest in the past year. Most have chanted for Tibetan freedom and the return of their spiritual leader, the Dalai Lama, who fled to India amid an abortive uprising against Chinese rule in 1959.

Many Tibetans resent Beijing's heavy-handed rule and the large-scale migration of China's ethnic Han majority to the Himalayan region. While China claims Tibet has been under its rule for centuries, many Tibetans say the region was functionally independent for most of that time.

"Chinese forces are responding with lethal force to Tibetans' ever-growing calls for freedom," Free Tibet director Stephanie Brigden said in a statement today.