A man who allegedly threw a 2-year-old girl in a stroller to the ground leaving her critically injured after a dispute with the girl's mother has been criminally detained, Beijing police said.

Media reports said the man, sitting in the front passenger seat of a white car driven by a male companion, gestured to a woman to move away so that the car could be parked near a bus station in Beijing's Daxing district at around 8:50 pm on Tuesday.

The woman, who was checking her child in a stroller, refused to move.

The reports said the enraged suspect got out of the car, attacked the woman and then lifted the 2-year-old girl in the stroller over his head before throwing her to the ground.

The other man also allegedly hit the woman before both men made off in the car.

Beijing Times reported on Thursday that the girl is in critical condition in the intensive care unit of Beijing Tiantan Hospital affiliated to Capital Medical University.

Doctors said she sometimes stopped breathing, but the hospital could not be reached for comment on Thursday.

The municipal public security bureau set up a special team to collect video evidence at the scene and to seek information from residents.

After a preliminary investigation, police said the suspect, surnamed Han, is a 42-year-old former convict from Fangshan district.

Han was released earlier this year after being imprisoned for theft, they said.

He was arrested at a spa center in Fangshan at about 3 pm on Wednesday and the car was found in the city's Haidian district, police said.

Han has been detained for intentional homicide and the case is under further investigation.

A witness, surnamed Zhou, who runs a noodle restaurant near the scene, said he heard a loud noise and saw a man in dark clothing beating a woman dressed in white.

"My restaurant is about 10 meters from the scene, but I could hear a hitting sound," Beijing Times quoted Zhou as saying.

The attack comes after a Jilin man kidnapped and killed a 2-month-old baby in March.

Many netizens on Sina Weibo, Chinese largest Twitter-like service, said the Beijing suspect is worse than Zhou Xijun, 49, who was sentenced to death for the baby's murder and ordered to pay a fine of 50,000 yuan ($8,100).

One netizen wrote that anger from a dispute between two adults in Beijing should not be vented on an innocent child.

Many Internet users are hoping that the girl recovers.

One netizen using the micro blog said her son is the same age as the girl in the case, and hopes that the toddler will pull through.