Li Heping said he was attacked with fists and electric batons and held for about five hours Saturday night. He said he was forced into an unmarked car by unidentified men after leaving his Beijing office.

"They covered my head and drove me to somewhere far away and brought me to a basement and beat me," Li told The Associated Press in a telephone interview. "They said you out-of-town lawyers are making trouble in Beijing, making it unstable."

The alleged attack on Li came the same day a dissident in eastern China who wrote about local corruption was arrested on charges of subverting state power. Also over the weekend, police detained the son and brother of Ye Guozhu, a Beijing resident serving a four-year prison sentence for disturbing the social order after he applied for a permit to hold a protest against forced evictions.

China's ruling Communist Party has taken some steps to appear more open ahead of the Beijing Olympics next summer, such as loosening restrictions on foreign reporters.

But critics say its grip on dissent has in fact tightened under President Hu Jintao. Controls seem to be ratcheted up as China prepares to hold its twice-a-decade Communist Party congress at which some new senior leaders will be appointed. The meeting, which begins Oct. 15, will set policy for the next five years.

Li, who said he was left with bruises and a swollen face, didn't know if the attack was related to the congress.

"They shouldn't do this during the 17th Party Congress. Aren't they going out of their way to cause trouble?" he said.

The lawyer said he was dropped off near some woods after the attack and walked a long distance until he found a taxi to take him home. He said he was being followed around the clock by security agents.

Li said he wasn't sure if he would be able to continue working. He returned to his office the day after the attack and found his lawyer's license was missing. A portable hard drive and his computer memory had been wiped clean, he said.

The lawyer's clients have included Chen Guangcheng, a blind activist who helped villagers file a lawsuit accusing local officials of forcing them to undergo abortions or sterilization. Cases this year include that of a Falun Gong practitioner whose family members were detained, and four farmers who were wrongly accused of murder, he said.

Telephones at the Beijing public security bureau, which often monitors the activities of dissidents, rang unanswered on Wednesday. The general inquiry line of the state security bureau was not answered.