THE dissident community in Beijing has expressed concern about the fate of other detained activists. Professor Xu Liangying said the authorities might now take a tougher line against them. 'In the next step, the authorities may sentence the others like [former student leader] Wang Dan to jail or reform through labour. I'm very worried about Wang's situation,' he said. The retired historian of physics at the Chinese Academy of Sciences condemned Wei's sentence as a huge step back for China's human rights. 'As far as I know, Wei has no thoughts of trying to subvert the Chinese Communist Party or the Government,' Professor Xu said. 'He opposes violence to overturn the authorities. It is impossible to charge him with subversion. That's totally groundless.' Wei's first jail sentence - 15 years for 'counter-revolutionary activities' - was also unwarranted, he said. The 75-year-old campaigner also warned against other 'savage' action taken by the Government, including the missile tests and military exercises near Taiwan, and the tough stance towards the Dalai Lama. 'This Government is not sober,' he said. 'It is very dangerous and unreasonable. It's just messing things up.' Professor Xu earlier organised a petition urging China to treat dissidents with tolerance and alter its stance towards the 1989 pro-democracy movement. Wang Dan's mother said she was worried her son might be the next victim. Wang, a former student leader of the 1989 democracy movement, has been detained for more than six months without charge. Wang Lingyun said she had neither seen nor heard from her son since his detention. 'It's difficult to say if Wei's condemnation will affect my son's situation . . . The legal system here is not sound,' she said. 'It is easy to frame up a person and send him to jail.' The wife of jailed dissident Chen Ziming, Wang Zhihong, yesterday said she had been closely followed by police in the past few days.