Yesterday Chinese authorities ordered government and security forces in Tibet to crush any signs of support for the Dalai Lama as the 50th anniversary of an anti-Chinese uprising neared.

Zhou Xiujun, the owner of a grocery shop in Lithan, said she witnessed a small protest near the county's main vegetable market on Sunday that escalated into a much larger one about lunchtime on Monday. On the second day, she said she saw several hundred Tibetans gathered downtown, shouting "long live the Dalai Lama" - the spiritual leader of Tibetan Buddhists who lives in exile in India. In just a few minutes, she said, squads of police arrived and a melee ensued.

At least one Tibetan protester was swinging a stick, she said, and others were throwing stones. The policemen subdued them using what she called "electronic sticks" and tear gas.

The London group Free Tibet said "at least 24 Tibetans were detained after the incidents" and "two people were carried away by police". The extent of their injuries was unknown. In India, the Tibetan Centre for Human Rights and Democracy said 21 people were detained. It said two men were badly beaten and suffered severe injuries.

Officials from the county government, police and the tourism office of Lithang, which is located in the mountains of the Gardze Tibetan Autonomous Prefecture in Sichuan province, confirmed an incident had taken place but declined to provide details. The activist group, Free Tibet, said these were the largest protests in the region since violence last year which left at least 18 civilians and one police officer dead. Since last March, Chinese security officials have gone to great lengths to seal off Tibet. No foreign journalists, except on escorted tours, have been allowed in the region and few Tibetans have been allowed to leave. Zhang Qingli, the Communist Party secretary for the largest autonomous Tibetan region in China, is a hardliner known for his strike-hard, no-tolerance approach to quelling unrest.

As the anniversary next month of the 1959 Tibetan uprising approaches, the crackdown has become harsher, residents say. In the capital of Lhasa at least 81 people have been detained over the past few weeks, Tibetan groups said.

The Washington Post, Agence France-Presse