BEIJING — The wife of China’s Nobel Peace Prize winner said late Sunday that Chinese authorities had allowed her to visit husband Liu Xiaobo in prison over the weekend, then placed her under house arrest on her return to Beijing.

Liu Xia had disappeared from public view for two days following Friday’s award of the Nobel Peace Prize to Liu Xiaobo. According to a Twitter posting on an account that she has used previously, the authorities took her to the prison in the northeast province of Liaoning, where he is being held.

After returning to the capital Sunday, Liu wrote in her Twitter note: “I don’t know when I’ll be able to see everybody.” She said the house arrest had begun on Friday, and her phone was also cut off now.

Repeated attempts to call her prompted a recording that her cell phone was turned off.

It was unclear if Chinese authorities knew that Liu apparently was using her Twitter account, or whether they’d allowed it to cool speculation about her wellbeing. Mo Shaoping, whose law firm represents Liu Xiaobo, had said less than an hour before the note appeared that he had no idea where Liu Xia was.

“I think there is very little doubt that she is under either custody or orders from the police to make herself scarce,” said Nicholas Bequelin, a Hong Kong-based researcher for Human Rights Watch’s Asia division.

As Liu Xia revealed her whereabouts, China’s ruling Communist Party appeared to still be weighing its response to the very public challenge to its authoritarian rule that the prize represents. Liu Xiaobo is serving an 11-year sentence for his role in drafting a political manifesto calling for democratic reforms in China, and the Nobel committee made clear it had chosen him in part as a rebuke of Beijing’s authoritarian rule.

Observers said the award, at the very least, is a foreign relations setback for China, and depending on what the government does next could turn Liu Xiaobo into a galvanizing figure for the splintered domestic dissident community.

“It’s a significant crisis for the party leadership … we may have to wait a little bit before the instructions come from the top leadership,” Bequelin said.

Concerns for Liu Xia were magnified by reports of Chinese government pressure on those sympathetic to Liu Xiaobo.

The New York offices of PEN, an international free speech advocacy group, confirmed that almost a dozen members of the independent Chinese PEN Center – of which Liu Xiaobo is a former president – had been harassed after the prize announcement Friday evening.

Eight Chinese PEN members were taken in for questioning-and-warning sessions with officials – a process known euphemistically as “having tea” – two more were put under house arrest and one was put in detention for eight days, New York PEN said.

China’s government over the weekend continued to prevent widespread dissemination of news about Liu’s award.

While it was possible to access foreign media sites and use special software to circumvent censorship, the vast majority of Chinese most likely did not know that one of their own had won the Nobel.

English-language publications under state control quoted a Foreign Ministry statement that called Liu a criminal. The Global Times said of Liu, the Dalai Lama and other critics of the Chinese government that “all attempted to sabotage the long-term guiding principles set out by the Party, and they have not been well received in China.”