Four pupils have been confirmed dead after a section of a middle school's wall collapsed on them in central China's Hunan province on Monday due to persistent heavy rain.

Six students from Miaowan Primary school in Hengyang county in the city of Hengyang were buried by the collapsed wall of Huishui Middle School at about 7:30 a.m., when they were en route to school, the city's publicity department said.

Two of the pupils were killed on the spot, one died on the way to hospital and another died in hospital. The remaining two students are still being treated in hospital.

Further investigation into the cause of the accident is under way.

Torrential rain battered Hunan over the weekend, leaving 1.09 million people affected, 80,400 hectares of cropland damaged and 1,568 houses toppled with direct economic losses of 840 million yuan (133 million U.S. dollars).