Beijing: A knife-wielding woman attacked children at a kindergarten in China’s southwestern city of Chongqing on Friday, injuring 14 of them. Police say a 39-year-old woman carrying a kitchen knife entered the school in Banan district as the children were in the playground.

The woman, whose surname was given as Liu, has been arrested, Hong Kong-based South China Morning Post quoted a local state-run Chongqing Broadcasting Group as saying. The motive behind the attack is unclear, though some reports on social media say the woman had a grievance against the government.

A mobile recording shared by the broadcaster showed the alleged suspect being dragged away by police, as well as an injured child lying on a hospital stretcher. A screenshot of a WeChat group said “a woman and her husband were arguing, and to take revenge against society she stabbed the children at the kindergarten with a knife”, the report said. China has faced a string of unrelated knife attacks in school and kindergartens in recent years. They have usually been carried out by people seeking revenge against officials or individuals, or who are suffering from mental health problems. On June, a 29-year-old man fatally stabbed two children outside a primary school in Shanghai, while nine schoolchildren were stabbed to death in a county in Shaanxi province in April, the report said.

Meanwhile, the toll from a coal mine accident in eastern China rose to eight as the bodies of five more miners were retrieved, local authorities said on Friday. The accident happened on Saturday after a rock burst ripped through a coal mine of the Longyun Coal Mining Company Ltd in Yuncheng county of Shangdong province, leaving two dead and 22 trapped in the tunnel.

Two bodies were retrieved underground early Thursday morning and three others were found in the afternoon, the rescue headquarters said. While one person has been rescued, 13 miners are still trapped inside. Only one person has been rescued. Thirteen miners are still trapped and rescuers are racing against the clock to locate them from two rescue passages, state-run Xinhua reported.

Rock bursts are often caused by fractures in rocks due to wear and tear from mining. Mining accidents are common in China. However, the number of deaths have reduced at mines in recent years.