Eight children were hurt on Monday when a staff member at a day care centre for the children of migrant workers in China's eastern city of Shanghai went on a stabbing spree, local media said.
The attack took place around midday at a temporary day care facility in an eastern suburb of Shanghai, the Xinmin Evening News said on its website.
A woman who has worked at the centre for several years used a box cutter to slash at children, all between three and four years old, the newspaper quoted witnesses as saying.
"Adults and children were all screaming 'Help'", a resident said.
The suspect, who is believed to have psychiatric problems, has already been detained by police, the newspaper said. Her name was not given.
One of the eight children was seriously injured. A local hospital official told AFP the hospital had received eight children from the school, but declined to comment on their condition.
The attack is the latest in a string of violence against children at China's schools since last year, which has brought heightened security and calls for investigations into the root causes of such acts.
In August last year, a man wielding a knife killed three children in a kindergarten in China's eastern province of Shandong.