More than 30 Chinese intellectuals have been detained, warned or placed under house arrest in a crackdown aimed at stifling celebration following the award of the Nobel peace prize to the imprisoned democracy advocate Liu Xiaobo.

There are concerns for the laureate’s wife, Liu Xia, who has not been seen since she went to visit her husband in Jinzhou prison earlier today, and whose phone line has been cut.

She did, however, tweet today that she had visited her husband and that he had been told yesterday that he had won the award. She said he had cried and dedicated his prize to the “dead spirits of Tiananmen”.

Zhang Yu, the Stockholm-based head of the Writers in Prison Committee of the freedom of expression group, Independent Chinese PEN Centre (ICPC), called the authorities’ reaction predictable and stupid. “They have tried to block the flow of information on the internet, detain people and cut telephone communications … I’m sure they have planned for this.”

The Norwegian Nobel peace prize committee announced on Friday that Liu, a former literature professor who co-drafted the Charter 08 campaign for increased political liberties in China, was this year’s winner.

A host of world leaders including Barack Obama, Archbishop Desmond Tutu and the former Czech president Vaclav Havel commended the decision, but the Chinese government responded with fury.

The foreign ministry summoned the Norwegian ambassador and declared the decision a “blasphemy” and insult to the Chinese people.

Censors blacked out foreign broadcasts of the announcement and police were mobilised to choke any sign of domestic support for Liu.

About 20 of those targeted by the crackdown were at a celebration party in Beijing on Friday night that was broken up by police. Three are now under eight days’ administrative detention for “disturbing social order”, while the others have been put under house arrest or heightened surveillance.

“There are two police outside my apartment building. I can’t go out,” said Liu Jingsheng, a recipient of the PEN/Barbara Goldsmith Freedom to Write award. “This kind of thing happens from time to time in Beijing during the People’s Congress and other politically sensitive periods, but it is tougher now.”

Lawyer Teng Biao said police had prevented him from meeting journalists and had warned him not to talk about the award or attend a celebration banquet.

The authorities appear to have focused particular attention on the ICPC, of which Liu was a member. The group’s deputy secretary general Jiang Bo is among at least 10 members who have been warned. Two are under house arrest and one – Zhao Changqing – has been detained.

Supporters hope that Liu Xia will collect the prize on behalf of her husband at the award ceremony in Europe later this year. If she were then to be denied re-entry into China, they say this might pave the way for the authorities to release Liu Xiaobo before the end of his jail term so he could join her overseas.

This scenario seems optimistic given the Chinese government’s recent unwillingness to release political prisoners, but the award has inspired hope.

Jiang Danwen, the deputy secretary general of ICPC, said police had warned him not to comment on the prize and were now parked outside his Shanghai home. He said, however, that the inconvenience was worthwhile.

“Actually I feel very happy. The reaction shows the award has really shocked the government.”