Authorities in Tibet and restive parts of western China were on heightened alert Tuesday for possible unrest on the 50th anniversary of a failed uprising against Chinese rule as the Dalai Lama said Tibet had become "hell on earth" under Beijing's control. In a speech marking the anniversary of his flight from China, the exiled Tibetan spiritual leader said decades under Chinese martial law and hard-line policies such as the Cultural Revolution had devastated the Himalayan region, leading to the deaths of hundreds of thousands of Tibetans. "Even today, Tibetans in Tibet live in constant fear and the Chinese authorities remain constantly suspicious of them," he said from his home in Dharmsala, India, denouncing the military's "brutal crackdown" in Tibet after anti-Chinese protests broke out a year ago. After the Dalai Lama's speech, thousands of young Tibetans took to the streets in Dharmsala, chanting "China Out!" and "Tibet belongs to Tibetans!" Protesters also held marches in support of the Tibetans in New Delhi, Seoul and Canberra, Australia.