The speaker of Tibet's parliament-in-exile on Tuesday accused China of turning the Himalayan region into a giant prison camp as he opened the biggest meeting of the Tibetan leadership in four years.
"A state of undeclared martial law continues to remain in force in Tibet," Penpa Tsering said in an opening address at the conclave held in Dharamshala.
"(China) has converted Tibet into a territory resembling a prison camp."
The meeting comes ahead of an expected change in leadership in Beijing and is the first such gathering since the Dalai Lama passed on his mantle as political leader of the Tibetans to prime minister-in-exile Lobsang Sangay.
Some observers have suggested that China's president-in-waiting Xi Jinping may be more flexible on Tibet and offer to restart talks with the exiled leadership.
A spate of self-immolation suicides by Tibetan monks has alarmed the exiled leadership and Tsering said they reflected a sense of despair.
"The question (is) how and in what ways we, the Tibetan people living in exile, should respond to the tragic situation in Tibet today," he said.
"Over the past 60 years the Chinese government has continued to pursue a policy of assimilation designed to obliterate the ethnic identity of the Tibetan people.
"The situation in Tibet became so severely unbearable that to our knowledge thus far 51 people, our flesh and blood brethrens, have been driven to sacrifice even their very lives by setting themselves on fire. Forty-one have died."
International pressure groups also say that there have been 51 attempted suicides by burning.
The Dalai Lama, who remains the Tibetan spiritual leader, has condemned self-immolations and blamed them on the hardline Chinese rule in Tibetan-populated areas.
Tibetans have long chafed under China's rule over the Tibetan plateau, saying Beijing has curbed religious freedoms and their culture is being eroded by an influx of Han Chinese, China's main ethnic group.