Chinese police are clamping down on the nation's beleaguered dissidents to ensure visiting U.S. vice president Joe Biden does not meet any activists during his trip, rights defenders said.
Police have stepped up surveillance on dissidents and warned them against making any high profile protests or attempting to meet Biden during his five-day visit, they said.
Biden did raise human rights concerns during his meetings with Chinese leaders, U.S. officials said, but they refused to go into details of whether any individual cases were raised.
Before the visit, Washington appealed to China to free rights lawyer Gao Zhisheng, who has not been heard from since last year, and restore the rights of dissident writer Ran Yunfei, released from detention earlier this month.