© Agence France-PresseEight children have been hurt after 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
Eight children were hurt on Monday when a staff member went on a stabbing spree at a day care centre for migrant workers' children in the Chinese city of Shanghai, local media said.

The female worker used a box cutter to slash at children aged between three and four years old at the "Little Happiness Star" nursery in an eastern suburb of Shanghai, the Xinmin Evening News said on its website.

"Adults and children were all screaming 'Help'," it quoted one witness as saying.

The incident was the latest in a series of violent attacks against children that have forced the authorities to increase security and brought calls for further investigation into the root causes of such acts in China's schools.

The suspect, who is believed to have suffered from psychiatric problems, has been detained by police, the newspaper said. Her name was not given.

One of the eight children was seriously injured in the attack, reports said. A local hospital official told AFP the hospital had received eight children from the school.

Worried parents gathered outside the day care centre after the incident in Shanghai's Minhang district, home to many of the city's migrant workers.

District authorities could no immediately be reached for comment.

At least five major attacks took place at schools in China last year, killing 17 people -- including 15 children -- and injuring more than 80.

Two of the attackers were executed and two others committed suicide. The suspect in the fifth attack was sentenced to death in June 2010.

And in August last year, a man wielding a knife killed three children in a kindergarten in China's eastern province of Shandong.

Some of the attackers were known to have mental health problems, and experts say the assaults show that China is paying the price for focusing on economic growth while ignoring problems linked to rapid social change.

Studies have described a rise in the prevalence of mental disorders in China, some of them linked to stress as society becomes more fast-paced and socialist support systems wither.

Reports said the day care centre where Monday's attack took place had more than 60 children and more than 20 staff. It was registered with authorities, and had been in operation for three years.