A Chinese singer who triggered a free speech debate by venting about bombing government offices will be released from detention without criminal charges, her lawyer said Wednesday, in an apparent U-turn by authorities.

Wu Hongfei said online she wanted to target Beijing's housing authority and a neighbourhood committee, soon after a man set off a homemade device at the capital's airport, citing grievances with local government.

She was detained by police following her comments on the Sina Weibo microblogging site, and media reported she was being held on suspicion of "fabricating fake terrorism information", an offence that carries a maximum of five years in jail.

She should be released Friday -- 10 days after being taken in -- after paying a 500-yuan ($80) fine, her lawyer Chen Jiangang wrote on Tencent Weibo, another microblog service.

But the singer "has concerns about whether she will continue to face interference after regaining her personal freedom", Chen added.

Chen told AFP by phone his Sina Weibo account had been deleted since he took the case -- along with a second one he set up afterwards.

His name, when combined with the word "lawyer", was blocked from being searched on Sina Weibo on Wednesday.

Chinese authorities censor the Internet closely to avoid social unrest, sometimes deleting what they consider troublesome accounts and routinely banning sensitive search terms.

In an informal online poll run by state broadcaster CCTV, 80 percent of voters did not think Wu's words constituted a crime.

Another of her lawyers was quoted as arguing her words did not pose a credible threat and were spoken in anger.

The airport bomber, Ji Zhongxing, was a former motorcycle driver who despaired at his failure to win redress for what he called a 2005 police beating in southern Dongguan city that left him paralysed, though authorities there said his claims lacked evidence.

The blast destroyed Ji's hand and injured an officer, but his story triggered widespread sympathy and an outpouring of resentment at abuse by local authorities.

He has been formally arrested and could face three to 10 years in jail, his lawyer told AFP this week.