Witnesses of the multiple stabbing in Chengdu on Sunday night said the attacks were brutal.

After a bus on the No 42 route left a stop in downtown Chengdu at about 9 pm on Sunday, a middle-aged man took out a knife about 20 centimeters long and began stabbing passengers arbitrarily, footage from the bus camera showed.

The driver stopped the bus and opened both doors to allow passengers on board to flee. As the suspect fled, he also stabbed passersby.

Holding a mop, the bus driver chased the man, and some people in the street tried to stop him.

A few minutes later, policemen arrived at the scene, near Caojiaxiang Police Substation, and fired shots into the air in an attempt to subdue the suspect.

When that failed, a policeman shot the man in his right leg, disarmed and arrested him.

"Although it is about 300 meters from where the bus stopped, casualties were heavy," said Yang Fuqing, a nearby bicycle repairman.

Yang saw a short man with closely cropped hair and wearing a red T-shirt stab the chest of a woman walking with her husband and then the stomach of a 10-year-old walking with her nanny. The man also stabbed the stomach of Yang's 51-year-old uncle Yang Zeyun who stood beside him.

The woman later died in a hospital, as did three other victims.

Together with one man and woman in their 20s, the pupil, Zhu Qi, and Yang Zeyun are in intensive care units on the fourth floor of the No 416 Hospital of the China National Nuclear Corporation, said a medic at the hospital surnamed Fan.

"Zhu Qi's spleen was removed. None of the four is out of danger," she said.

According to the city's emergency center, which sent all the victims to hospitals, the other seven victims being treated in four other hospitals were severely wounded.

— Huang Zhiling