Authorities in the Chinese capital have detained an outspoken singer on public order offenses after she tweeted that she would like to "blow up" a government department, activists said.
Beijing-based rights activists said they had been in touch with Wu Hongfei's friends and the local police station after she was called in for questioning on Monday following her post at the weekend.
"She said she had sent out a tweet with something about an explosion, but she didn' t go into the details," said Beijing-based online activist Hu Di, adding that Wu had told him she was being criminally detained.
Meanwhile, fellow Beijing activist Liu Yanping said officers at the city's Chaoyang district police department had told her the charges were "picking quarrels and starting a fight."
"The police officers in charge of her case told me she is being held under criminal detention for picking quarrels," Liu said.
Outspoken artist and social critic Ai Weiwei said he thought Wu's tweet wasn't serious.
"I think that this should come under the category of a joke," Ai said. "She, and everyone else [who tweeted about blowing stuff up] are blameless, and there is no likelihood that they will do anyone any harm."
"I think everyone thinks this is ridiculous, and this isn't the only instance; there have been several others."
"Every time the authorities do something like this, they create a public crisis of confidence in the rule of law in China," Ai said.
Calls to the Chaoyang district police department went unanswered during office hours on Tuesday.
Wu's post targeted the Beijing municipal government's housing commission offices at a time when many young Chinese are finding it increasingly difficult to buy homes.
Rights activist Hu Jia said he was working to find a lawyer to represent Wu.
"I told Wu Hongfei's family we would find her a professional lawyer who is also her friend," Hu said. "We will decide on this in the next couple of days."
Beijing-based rights lawyer Chen Jiangang said he was willing to take Wu's case, subject to agreement from her family.
"According to my understanding of the facts so far, I don't believe that [Wu's actions] amount to a crime," Chen said. "There's a big difference between sending out a tweet and actually committing a crime."
He said he would seek a meeting with Wu as soon as possible, if he was instructed to act by the family.
Wu's detention came after disabled petitioner Ji Zhongxing apparently set off an explosive device at a Beijing airport on Saturday, injuring no one but himself, following a protracted attempt to complain about his paralysis, which he says is the result of a police beating in the southern city of Dongguan.
However, the New York-based Human Rights Watch (HRW) said Wu's detention is probably politically motivated after her previous criticisms of the ruling Chinese Communist Party.
"The Chinese government has frequently used criminal charges to punish and intimidate individuals for expressing opinions critical of the government," HRW researcher Maya Wong told the Associated Press.
"Wu has been very outspoken in the past, and it is hard not to suspect that her criminal detention is the result of political retribution."
Police have detained two men who apparently threatened to blow up the airport and a video arcade respectively, in the wake of Ji's protest, according to the AP.
Wu has spoken out against social ills in the past to more than 120,000 followers on her Sina Weibo account.
She also tweeted in support of Ji after the explosion at the airport.
"If he is a thug, I wish this government would foot the bill for this thug," she wrote.
"It is not that I encourage violence, but I really detest a system that pushes innocent people to violence. Everyone should be able to appeal to justice," Wu wrote.
Ji's current whereabouts are unknown.
Reported by Xin Yu for RFA's Mandarin Service, and by Grace Kei Lai-see for the Cantonese Service. Translated and written in English by Luisetta Mudie.