Fire swept through a passenger bus in Zimbabwe, and police said on Friday that more than 40 people died and at least 20 were injured, some with severe burns.

Police spokesperson Charity Charamba said she did not have details about the cause of the accident on Thursday night.

A photograph posted on Twitter by the Zimbabwe Red Cross shows the remains of a bus that was completely incinerated. The Red Cross said its teams responded to a 'horrific accident' involving a bus heading to neighbouring South Africa at around midnight.

The accident happened in Gwanda district, about 550 km south of Harare, Zimbabwe's capital.

Last week, a collision between two buses in Zimbabwe killed 50 people and injured about 80.