China's hand-picked Panchen Lama is presiding over a key Buddhist ritual being held in Tibet for only the first time in 50 years, in a move criticized by overseas Tibetan groups.

The official Xinhua News Agency says the second-highest figure in Tibetan Buddhism was present for the Kalachakra instructions that began Thursday morning at his home monastery in southwestern Tibet. The report says an estimated 50,000 Buddhists attended.

Beijing named its own Panchen Lama after rejecting the boy who was recognized by the Dalai Lama, the highest figure in Tibetan Buddhism. The government has long vilified the Dalai Lama as a separatist.

London-based Free Tibet said the resumption of the ritual was intended to bolster the standing of a cleric who many Tibetans regard as a fake.