Days before the start of the Beijing Olympics, a pro-Tibet activist group is criticizing China for intensifying a crackdown on Tibet and sealing off virtually the entire Tibetan plateau to "hide its repression." In a report released Tuesday, the International Campaign for Tibet said that since anti-China protests erupted in March, armed soldiers have surrounded the Himalayan region's Buddhist monasteries. Hundreds of Tibetans, including students, monks, nuns and farmers, it said, have been detained or "disappeared," and people in the Tibetan capital Lhasa sleep in their clothes, "fearful of a knock on the door in the middle of the night." "China has dramatically tightened security in Tibet and announced new 'anti-terror' plans in order to prevent any possible embarrassment to the ruling Communist Party before a worldwide audience during the Olympics," said the Washington-based group's report. Leaders in Beijing see the Olympics, which begin Friday, as a chance to showcase their country's emergence as a new world power. Critics are increasingly using the attention the games are attracting to condemn what they say is China's failure to follow through on pledges to improve human rights that were included with China's bid to host the games. Protests in Tibet, initially led by Buddhist monks, started peacefully on March 10, the anniversary of a failed Tibetan uprising against Chinese rule. They became violent four days later as Tibetan ...