At least 42 passengers have been confirmed dead, Zimbabwe police said on Friday, after a suspected gas tank exploded on a bus, with pictures showing the burnt-out wreckage of the vehicle.

"At the moment we know that more than 42 people died," police spokesperson Charity Charamba told AFP after the accident late on Thursday, with state media reporting a gas tank belonging to a passenger was believed to have exploded.

"Our police officers are at the scene," Charamba added.

The state-owned Herald newspaper said on its Twitter feed that "it is suspected a gas tank belonging to one of the passengers caused the inferno in the bus.

"Dozens have been confirmed dead and several others injured through burns."

The Zimbabwe Broadcasting Corporation published photographs showing the destroyed vehicle on a highway from the South African border crossing to the second city Bulawayo

Last week, 47 people were killed when two buses collided on a road between the capital Harare and the eastern town of Rusape.

President Emmerson Mnangagwa said road safety had to be improved after that crash.

Traffic accidents are common in Zimbabwe, where roads are riddled with potholes due to years of underfunding and neglect, and driving standards can be poor.

In June last year, 43 people were killed in a bus crash in the north, along the highway leading to neighbouring Zambia.

BDST: 1836 HRS, NOV 16, 2018

AH