A hammer-wielding man wounded 20 children in an attack at an elementary school in Beijing on Tuesday with three suffering serious injuries, local authorities said.
The suspect was apprehended at the scene and an investigation has been launched, the statement said.
Police declined to comment by telephone when asked about the attack.
Several of the pupils were taken to the intensive care unit of the nearby Xuanwu Hospital.
A relative escorts a child from an elementary school where an attack took place in Beijing.
Authorities did not say what weapon, if any, was used.
"The details are still not clear", one parent wrote on WeChat.
Other reports suggested that the attacker may have worked as a janitor at the school in the past. It is not like what everyone is saying, he did not use a knife. The injured children have been hospitalised. We have been communicating with parents but some of them have gone to the hospital to see their children.
The agency also noted that violent crime is rare in China but there has been a series of knife and axe attacks in recent years, many targeting children.
A doctor at the hospital posted on social media: "The mayor today came to the hospital to wait with us while the children were being medically treated".
In October, a 39-year-old woman stormed a kindergarten in Chongqing, southwest China, injuring 14 kids with a kitchen knife.
The killer, who said he had been bullied when he attended the school in northern China's Shaanxi province, was executed in September.