BEIJING (AP) — A Chinese court has sentenced a democracy advocate who started several online groups and participated in political discussions to eight years in prison on the charge of inciting subversion.

Cao Haibo's sentencing comes as China prepares for a once-in-a-decade leadership transition that kicks off Nov. 8. In the lead up to the opening of the Communist Party congress in Beijing, authorities have intensified pressure on activists, dissidents and lawyers around the country.

Attorney Ma Xiaopeng said a court in the southern city of Kunming notified him Thursday that Cao, 27, had been sentenced in a secret hearing Wednesday. Ma said the court violated Chinese law that states all verdicts must be announced in open hearings.

Cao's wife, Zhang Nian, said she had not been contacted by the court about the hearing either and said the sentence was too severe.

"He didn't take any substantive action. All he did was express his opinions on the Internet. I think it is excessive of the court to give him such a harsh sentence for that," Zhang said, adding she would urge her husband to appeal.

Cao had been working at an Internet cafe in Yunnan province when he set up a website and a number of online groups to promote democracy and constitutional government when he was detained.

Rights groups say police entered his home in October last year and searched it before taking him away.

In May, he was tried by the Kunming Intermediate People's Court, which held a closed-door hearing because, it said, the case involved state secrets, according to Cao's lawyer Ma.

Ma said he did not know the reasons why the court convicted Cao of the charge of inciting subversion of state power because he has not yet obtained the verdict. Subversion is a vaguely defined charge frequently used to punish political critics. Imprisoned Chinese Nobel laureate Liu Xiaobo was sentenced to 11 years in prison on the same charge.

Calls to the court rang unanswered Thursday.

Chinese authorities have been ratcheting up restrictions on activists and government critics in the weeks ahead of the party congress. Beijing activist Hu Jia said Thursday police threatened him with "retaliatory measures" if he did not leave the capital for the duration of the meetings. Hu said he went back to his hometown in Huangshan of Anhui province a few days ago.

The wife of a prominent rights lawyer Jiang Tianyong said that Jiang was also compelled to travel outside Beijing during this period. Other rights lawyers either could not be reached by phone or said it was "very inconvenient" to talk.

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