More than 100 Chinese activists have signed and released an open letter asking that Nobel Peace Prize winner Liu Xiaobo be released from prison.
The letter released late Thursday and posted online also asks China's leaders to respond to the peace prize "with realism and reason."
China has responded angrily to the award, saying the West is using it to undermine China and calling Liu a criminal.
The literary critic and activist is serving an 11-year sentence for subversion after co-authoring a call for political reform in China.
Since the peace prize was awarded a week ago, a group of Chinese Communist Party elders has issued a separate public demand for more freedom of speech in China.
Meanwhile, dozens of activists have reported being detained or harassed by police over the peace prize and warned not to use the prize as momentum to make trouble.
Some of them also received threatening calls from police over the latest open letter even before it was released, said Xu Youyu, a professor with the Chinese Academy of Social Sciences who signed and helped prepare the letter.
The letter asks police to stop "these illegal actions."
"We thought we had to say something," Xu said by phone Friday. "The government is still doing the same things."
The letter also seizes on a series of recent public remarks by Premier Wen Jiabao, who made unusually direct calls for the communist system to evolve. Some of the remarks have been censored inside China.
"In a recent series of speeches, Premier Wen Jiabao has intimated a strong desire to promote political reform. We are ready to engage actively in such an effort," the letter says.
Xu said more than 120 people have signed the letter. A copy shows that signers include several well-known activists including constitutional scholar Zhang Zuhua, one of the people who worked with Liu to draft Charter 08, the call for further freedoms in China that got Liu sent to prison.
Other signers include activist lawyer Pu Zhiqiang and Li Datong, a veteran state newspaper journalist who was forced from a top editing job for reporting on sensitive subjects.