Blind legal activist Chen Guangcheng, one of China’s most prominent human rights advocates, has escaped from home imprisonment, activists said on Friday, but uncertainty over his whereabouts and fears about his health have worried supporters.

Chen, a self-schooled legal advocate who campaigned against forced abortions, had been restricted to his village home in Linyi in eastern Shandong province since September 2010 when he was released from jail.

His confinement and relentless surveillance with his family fanned protests by Chinese sympathizers and criticism from foreign governments and activist groups.

Chen’s reported escape and the furore it has unleashed could add to the headaches of China’s ruling Communist Party, which is striving to ensure stability and authority ahead of a leadership transition later this year.

Bob Fu, president of the Texas-based religious and political rights advocacy group ChinaAid, said in a statement that Chen was in Beijing and “100 percent safe”.