( dpa ) - The human rights lawyer Teng Biao has been missing since Thursday, Human Rights in China (HRIC) said on its website Saturday.
Eyewitnesses reported seeing the lawyer being dragged away in front of his apartment by unknown figures as he got out of his car, HRIC said.
In another case, the activist lawyer Li Heping was driven into by a police automobile as he brought his son to school. Li Heping and the son were however not injured, HRIC said.
HRIC is demanding a guarantee for the bodily protection of human rights lawyers in China.
The attacks on the lawyers show that Beijing is tightening its "stranglehold" on activists before the Olympic Games this summer, said Tim Parritt of Amnesty International Asia.
He demanded an independent and thorough investigation of the incidents. Amnesty International saw a possible connection between the disappearance of Teng Biao and charges that have been brought against the human rights and AIDS activist Hu Jia.
Teng Biao and Hu Jia criticized human rights violations in an essay called, "The real China and the Olympic Games 2008."