The whereabouts of rights activist Yang Maodong remained unclear yesterday as authorities stepped up surveillance of his associates in a hunger strike campaign in Beijing.
Contacted by a friend at 6pm on Wednesday, Mr Yang said he was being held in the Fuyou Street police station - where petitioners and protesters picked up at the nearby Zhongnanhai leadership compound are usually held - Aids activist Hu Jia said.
Mr Yang's mobile phone has since been turned off.
Mr Yang went missing on Wednesday after protesting at Xinhua Gate, the main entrance to the complex of buildings that serve as the headquarters for the Communist Party and central government near Tiananmen Square. He attempted to hold a two-hour hunger strike at the gate to protest against the government's violent handling of rural unrest in Taishi and Shanwei, Guangdong, the suppression of rights activists such as Gao Zhisheng, Lu Banglie and Zhao Xin, and the closure of the Bingdian Weekly and internet bulletin board Yannan BBS.
A worker at the Fuyou police station said no one surnamed Yang or Guo was being detained there. Mr Yang is also known by his pen name, Guo Feixiong .
Mr Hu, a close friend of Mr Yang and a member of the hunger strike campaign against the government's violent treatment of activists and petitioners, said he was under police surveillance yesterday, with seven plain-clothes officers stopping him from leaving his home after a 10-minute tussle in the morning.
'They knew I would be going to Xinhua Gate after tapping our phone conversation. They think it would be a threat if I made my way to the gate,' he said.
Another campaigner, Qi Zhiyong, said he was escorted in a police car when he went to get medicine from a hospital.
'At first they didn't let me go outside. After I told them I need to get my diabetic medicine, they asked me to go in their car,' said Mr Qi, who lost his leg in the 1989 Tiananmen Square crackdown.
Mr Gao, the campaign's co-ordinator, said two more activists would join the hunger strike. Mr Hu said they might step up their nationwide campaign, which began on Saturday.