The public and legal experts are split over whether police have overreacted by detaining of an outspoken singer after she allegedly threatened to bomb government offices in Beijing.

Wu Hongfei, lead singer of rock band Happy Avenue, was arrested in the capital on suspicion of "fabricating fake terrorism information", a crime that carries a maximum sentence of five years in prison, Legal Evening News reported on Saturday.

Wu Hongfei, lead singer for rock band Happy Avenue

Calls by China Daily to Beijing police went unanswered on Sunday, but Wu has not updated her Sina Weibo micro blog since July 22.

Wu, known for her candid criticism of the government, wrote on Sina Weibo on July 21 that she wanted to blow up a residential committee in Beijing and the Beijing Municipal Commission of Housing and Urban-Rural Development, an agency responsible for urban housing management. She did not say in her post why she had singled out these government offices, and no explanation has been given since.

The post was deleted, but not before it was forwarded hundreds of times.

Wu posted the message a day after a man from Fujian province set off a home-made explosive device at Beijing Capital International Airport, injuring himself and a police officer.

On the same day, Beijing police also detained two other men, both for allegedly threatening to set off bombs in public places in Beijing.

Huang Ming, vice-minister of public security, pledged to "severely punish" those who threaten to start fires, set off bombs or make hoax terrorist threats.

Jia Yan, a prosecutor in Tianjin, said it is inappropriate to post threatening statements after such a series of extreme acts and the singer should be educated or even punished.

"But criminal detention might be too serious. Administrative detention will be enough," he said.

People placed in criminal detention are likely to face criminal charges, while those deemed guilty of minor offenses are normally held in administrative detention. People can be held in administrative detention for up to 15 days without a trial or criminal charges being filed.

Central China Television, the State broadcaster, found in an opinion poll of 24,600 Sina Weibo users that more than 81 percent believe Wu's remarks do not constitute a crime, but they were inappropriate.

"She didn't really mean it, and she would never act on her words. They were just some remarks to vent that she had made many times before," said Zhang Peng, a business consultant and fan of the singer's in Beijing.

Zhang, who has been to several of Wu's shows, said she believes Wu is a person who follows her instincts, a quality that has made her popular.

Li Jinxing, one of Wu's lawyers, said he will meet his client on Monday, and will make a not-guilty plea.

"I think this case is of great significance, and it will become a landmark lawsuit in drawing a line between the freedom of speech online and committing a crime," he said.

A series of extreme acts across the nation in recent weeks have prompted concern for public safety.

A man reportedly suffering from mental illness was detained after he stabbed four passersby, including two children, in a downtown supermarket in Beijing on July 22. An injured woman died on the way to hospital.

In the Guangxi Zhuang autonomous region, a villager identified only by his surname, He, is accused of hacking two people to death and injuring four at a family planning authority building on Tuesday. On the same day, an ex-convict in Beijing was detained by police on suspicion of killing a 2-year-old girl by throwing her to the ground.