A group of relatives of victims of the bloody suppression of the 1989 Tiananmen democracy protests condemned China's police on Monday for rounding up supporters of Nobel Peace Prize winner Liu Xiaobo.
Numerous backers of Liu have disappeared and are believed to have been taken into police custody in recent days, including the head of the Tiananmen Mothers, Ding Zilin, according to another member of the advocacy group.
"We strongly condemn the government for taking away the personal freedom of Ding Zilin," the group member, Zhang Xianling, told AFP.
"This is a crime. We strongly protest, we call on the government to release Ding Zilin as soon as possible and allow her to contact her friends."
The group has issued a formal statement condemning the police action and demanding Ding's release, she said.
Members of the group have been unable to contact Ding and her husband Jiang Peikun for four days, as their phones have been cut off. Ding is believed to be in the eastern Chinese city of Wuxi, where she has a home.
After winning the award on December 8, Liu -- previously jailed for his involvement in the Tiananmen movement -- told his wife during a prison visit that he wished to dedicate the prize to the victims of the 1989 army crackdown.
China's communist government has lashed out at the award given to Liu, and police have placed his wife Liu Xia under house arrest and rounded up or issued warnings to numerous dissidents in the past 10 days, activists said.
According to Zhang, Liu's close friend and fellow writer Jiang Qisheng has also been missing for more than a week and is believed to be in police custody.
The 54-year-old Liu was jailed for 11 years in December on subversion charges after authoring a bold petition calling for democratic reform in one-party China.
Liu, a former university professor, helped negotiate the safe exit from Tiananmen Square of thousands of student demonstrators before tanks crushed the six weeks of peaceful protests in the heart of Beijing.
More than 600 Chinese scholars, activists and lawyers have signed an open letter calling for democracy and the release of Liu along with all other political prisoners as of Sunday night, up from 100 signatories on Friday.