By Own Correspondent| At least 20 children inside a Beijing primary school have been wounded following an attack by a male labourer, Chinese authorities have said.

This was revealed by the Xicheng district government on its social media account Tuesday.

According to the post, three of the children had serious but non-life-threatening injuries.

The suspect, only identified as Jia, was apprehended at the scene, according to the statement

However, all the children are receiving hospital treatment and an investigation has been launched.

A report by the Press Association alleged that the 49 year male attacker ,Jia, from northern Heilongjiang province, was employed through a labour service company to carry out maintenance work at the school. His contract was set to expire this month and had not been renewed.

As an expression of his dissatisfaction, Xicheng district said, Jia wielded a hammer that he normally used for work to injure students during a class.