Police say at least 21 people have been killed in Ghana after a tanker carrying gasoline overturned on a highway and exploded as people were trying to take the fuel.

Seth Oteng, a regional police commander, says the accident occurred on a highway between the towns of Tanoso and Techiman, 180 miles west of Accra, Ghana's capital.

Oteng says once the tanker began leaking, people rushed to try to collect the spilling gasoline. They died when a spark caused the fuel to explode, engulfing the area in flames.

An unknown number of injured people have been rushed to a local hospital.

Oteng says the cause of the tanker's accident was not immediately known.