A knife-wielding man has stabbed to death four primary schoolchildren in southern China, state media report, the latest in a series of such attacks in recent years.

The stabbings occurred on Friday in the Guangxi Zhuang Autonomous Region in southern China, the official Xinhua news agency said, citing local authorities.

The attack took place in the town of Pingshan in Lingshan county as the pupils were on their way to school, the report added, citing the county public security bureau.

Three of the children died at the scene and the other died later in hospital, the report said.

Police are searching for the suspected assailant, described as middle-aged, the report said.