A knife-wielding woman attacked and injured 14 children at a kindergarten in China's southwestern Sichuan province on Friday, authorities said.

Images and video footage circulating on social media show children in blood-soaked clothes, some with knife wounds on their faces. Angry parents also attacked the alleged knife attacker, who is dressed in red (right) and surrounded by police.

The 39-year-old assailant, identified only by her surname Liu, used a kitchen knife to slash students while they were returning to the classroom after morning exercises, said the Banan district public security bureau in Chongqing city on its official social media account.

Images and video footage circulating on social media showed a scene of chaos, as several children in blood-soaked clothes - some with knife wounds on their faces - walked out from the kindergarten in a daze.

Other videos showed angry parents beating the woman - who is surrounded by police - in outrage.

The victims were taken to hospital while guards and staff at the kindergarten restrained the attacker, said the police, adding that they were investigating. The statement did not give possible motives for the attack.

The attack took place at about 9.30am local time, according to the department.

Violent crime is rare in China compared with many other countries, especially in major cities where security is tight, but there has been a series of knife and axe attacks in recent years, many targeting children.

Such attacks are often blamed on people with mental illness or who have personal grievances. Knives are most commonly used, because gun controls are extremely strict in China.

In September, China executed a man convicted of killing nine students and injuring 11 in a knife attack at a middle school in the central province of Shaanxi./.

Reuters/AFP/CNA