BEIJING // Human rights campaigners have given a cautious welcome to the release late on Wednesday of the Chinese artist Ai Weiwei, saying many other activists remain in detention as part of a crackdown on dissent that began in February.
Mr Ai, who has achieved international renown as an artist but has angered the Chinese authorities over his support for political reform, was let out on bail for his "good attitude in confessing his crimes" and because he suffers from a chronic disease, according to police.
Mr Ai, 54, was arrested on April 3, and the Chinese authorities later said he was being held because a company he controlled had not paid taxes and had destroyed documents.
Mr Ai's detention came amid the arrest of more than 130 other political activists since online calls in February for protests in China to mirror those that have swept the Middle East. Human rights groups and western governments made high-profile calls for Mr Ai to be released.
Anu Kultalahti, a campaigner in the East Asia division of the London-based human rights organisation Amnesty International, said in Mr Ai's case the Chinese authorities had come under "enormous pressure from outside".
"[Some] other people have not been released," Ms Kultalahti said. "I don't think it's a sign of a relaxation of the crackdown necessarily. Certainly there's a crackdown still going on."
She added that many of those released had been "unusually silent", indicating "they've been threatened not to talk about their experiences".
Indeed, since his release Mr Ai has said he cannot talk about the case, only telling media he is happy to be free and is "fine". He cannot leave Beijing without permission, the Chinese authorities said yesterday.
At least eight activists are likely to face trial, probably on charges of "subversion of state power", according to Amnesty International, and others who have been released are under "illegal house arrest" or face other restrictions.
Dr Chung Chienpeng, an associate professor of political science at Lingnan University in Hong Kong, said Mr Ai's release may have been the result of "his profile and something particular to his case", rather than being an indication of a loosening of restrictions.
"The fear is if separate groups with different grievances coalesce, that worries the Chinese government," he said.
After Mr Ai's release, which coincides with a visit by the Chinese premier, Wen Jiabao, to Germany and the United Kingdom, the US State Department has called for other activists to be freed.
Hong Lei, a spokesman for the Chinese foreign ministry, called on foreign countries not to interfere in Mr Ai's case.
"China is a country under the rule of law. We hope the relevant countries respect China's judicial sovereignty," he said.
Mr Ai is the son of a distinguished poet, the late Ai Qing, who was detained by authorities during the rule of Mao Zedong, although he was back in favour with the authorities later in his life.
Although Mr Ai has had close ties to the Chinese authorities, providing input into the design of the iconic Bird's Nest Stadium used for the 2008 Olympics, he has angered the officials by exposing alleged corruption linked to the death toll of the 2008 Sichuan earthquake. He has also criticised the slow pace of political reform in China.
The Chinese government has always been "very selective" in how it punishes critics, said Ding Xueliang, a professor and political analyst at the Hong Kong University of Science and Technology.
It is not just question of "how offensive" their actions are, but how famous the individual is and the international pressure the Chinese authorities face.
"In Ai Weiwei's case, he's very famous. His detention has been widely reported and many international organisations and foreign governments and foreign politicians, not to mention the media, have issued very strong criticism," he said.
The Chinese authorities have become more eager to crack down on dissent recently because of an increase in the number of large protests in the country, even if these are not politically motivated, Dr Ding said.
"[Protests] have increased because … in their daily life, so many things are regarded by ordinary citizens as unfair, but effective channels to correct such wrongdoing become more restricted, so anger is always building up."