A student at a university in Beijing has killed his law professor with a kitchen knife, the Xinhua news agency reported on Wednesday, citing a police source.

Cheng Chunming, 43, a professor at the University of Political Science and Law in Beijing, was preparing to give a lecture on Tuesday when he was attacked by a 22-year-old student, who rushed into the classroom with a kitchen knife, the agency said.

The professor was "cut twice on the right side of his neck" and died of "excessive blood loss" in hospital, the source said. The fourth-year politics and management student then surrendered to police.

A help center has been set up at the university to provide counseling to both teachers and students.

The attack is the third such incident in China this month, and comes after a 23-year-old school teacher was killed by a student who stated that he hated "society and teachers."