Chen Yanfu, a 43-year-old man, stabbed and killed three children and a teacher at a primary school on Monday morning and injured five others in central China's Hubei province.

Chen later jumped to his death from the fifth floor of the school building at Dongfang Primary School in Yunxi county, Shiyan.

An initial probe suggests Chen was angry the school refused to allow his daughter to register for the new semester because she did not complete her vacation homework, police said.

Sept 1 is the first day of the new school year in most Chinese schools, including Dongfang Primary School. At around 10:40 am, while students were receiving their new textbooks, Chen stormed into two classrooms and stabbed one teacher and eight students with a fruit knife. The teacher and three students later died. One student who was seriously injured is still in intensive care, and the other four are out of danger, doctors said.

China has seen?a spate of attacks on school students over past years. According to incomplete research by journalists from Xinhua, at least 18 cases of violence have occurred on Chinese campuses since 2010, leaving 180 teachers and students killed or injured.