Both are founders of the independent China Democracy Party (CDP).

BBC Beijing Correspondent Carrie Gracie: Xu Wenli tried to exercise rights supposedly in the Chinese constitution

In Beijing, veteran activist Xu Wenli was handed a 13-year jail term. He was detained last month after setting up a Beijing branch of the CDP.

In a separate move, Wang Youcai received an 11-year sentence. His trial was held in the eastern city of Hangzhou on Thursday. A third CDP member, Qin Yongmin, is still on trial.

The United States has called Mr Xu's verdict deplorable. The Chinese authorities have warned that there will be a continuing tough line against dissent. They dismissed foreign criticism as interference.

Heavy security

BBC Beijing Correspondent Duncan Hewitt: "Government wants to send a strong message"

There was heavy security outside the courthouse in Beijing for Mr Xu's trial. Bystanders and journalists were prevented from entering the building.

Mr Xu's lawyer said he refused to defend himself against the charges, which he said stemmed from political persecution. Mr Xu's wife complained that he was not given time to prepare a proper defence.

The sentences came a day after another prominent dissident, Liu Nianchun, was freed from a labour camp and flown to exile in the US. Two other dissidents, Wei Jingsheng and Wang Dan, were flown to the US last year.

BBC Beijing Correspondent Duncan Hewitt says the move sends a clear signal that - after some uncertainty - the authorities are not prepared to tolerate any questioning of the Communist Party's leading role.

About 200 dissidents have signed a petition calling for the men's release.

National congress call

Over the past two years, China has signed two important UN rights treaties and won some praise for bringing its legal system closer to international standards.

The ruling Communist Party relaxed some controls on dissenting views among academics.

Mr Xu, 55, and other dissidents saw the more open atmosphere as an opportunity to form a democratic party.

He became openly involved in the CDP in November, organising the group's branch in Beijing and nearby Tianjin.

Shortly before his arrest, he called on party members and exiled dissidents to convene a nationwide congress.