China launched its most prolonged and severe crackdown on activists and dissidents in recent years ahead of the Nobel peace prize ceremony honouring the jailed writer Liu Xiaobo.
Scores – perhaps hundreds – of people have been placed under house arrest or surveillance, had communications cut off and been forced to leave the capital or prevented from travelling abroad. While such tactics are common before important events such as political meetings, it is rare for pressure to last so long and be applied so extensively. Amnesty International said it believed more than 250 people are affected.
"The scale and intensity are unprecedented. It is an attempt to prevent any voice supporting this prize coming from China," Nicholas Bequelin, the Asia researcher for Human Rights Watch, said.
"Activists feel this is worse than before the Olympics or sensitive anniversaries," Wang Songlian, of the Chinese Human Rights Defenders network, said.
The Nobel Peace Prize has been awarded in Oslo, Norway, but without the presence of laureate Liu Xiaobo, a jailed Chinese dissident.
An empty chair represented the 54-year-old writer and former professor, after the Chinese government barred him and his wife from attending the ceremony on Friday.
Thorbjoern Jagland, the Nobel committee chairman, said Liu had "done nothing wrong" and called on Beijing to release him in a speech at the ceremony.
"Liu has only exercised his civil rights. He has not done anything wrong. He must be released."
Jagland paid tribute to Liu's pro-democracy campaigning, most significantly for attempting to stop clashes on Tiananmen Square in 1989.
"Liu has told his wife that he would like this year's peace prize to be dedicated to 'the lost souls from the 4th of June'."
"It is a pleasure for us to fulfil his wish," Jagland said.