The death toll has risen to five after two buses collided Wednesday in northwest China's Gansu Province, local work safety watchdog said Friday.

Doctors are still trying to save two people who were badly injured in the accident, according to officials of the Work Safety Supervision Administration of Gansu. Three others received slight injuries.

The accident occurred around 4 p.m. on a provincial road in Wudu District in Longnan City in Gansu.

The accident involved a coach carrying 18 passengers and a minibus with eight passengers.

Four people died at the scene and a fifth victim died in hospital Friday.

Police are investigating the cause of the accident.