A newborn baby boy was rescued from a sewage pipe in a Chinese apartment building after being flushed down a toilet, state media said, provoking online outrage Tuesday.

"Fortunately the baby survived. But the person (who abandoned him) is still suspected of attempted murder," said an unidentified police officer, according to the official news portal hangzhou.com.cn.

Residents in Jinhua, in the eastern province of Zhejiang, called firefighters after hearing the two-day-old baby crying in the fourth-floor squat lavatory, the report on Monday said.

Attempts to pull him out failed, so rescuers sawed away a section of the 10-centimetre (four-inch) diameter pipe with the baby inside and took him to a local hospital.

Firefighters and doctors spent nearly an hour taking the tube apart piece by piece with pliers and saws and finally recovered the newborn, whose placenta was still attached, the report said.

From the time he was found till when he was taken out, the baby was stuck in the tube for at least two hours, it added.

The 2.3-kilogram (five-pound) boy suffered some cuts to his face and limbs and his heart rate was low at one point. He was put in an incubator and was in stable condition, the report said.

Police were still looking for his parents, it added.

The news triggered hundreds of thousands of comments on China's hugely popular weibos, services similar to Twitter, with users expressing good wishes for the baby and fury at those who presumably abandoned him.

"I can never accept or forgive the behaviour of dumping the baby with his placenta and umbilical cord attached into the toilet pipe," wrote a user with the online handle Jiding Jiajia.

"Can these people be called human beings? The animal to human ratio among the grown-ups is rising inexorably."

Another user, If-Free, said watching the rescue left her distraught.

"Seeing the little one wriggling and groaning as the pipe was torn apart bit by bit wrings my heart... You've lived through the hardest moment in your life and your future will definitely be smooth," she said.

Chinese babies born out of wedlock are sometimes abandoned because of social and financial pressures. The country's one-child policy can also mean heavy fines for couples who have more than one baby.