A road tanker carrying petroleum products exploded in southern Nigeria on Wednesday killing at least 20 people.

The incident occurred at a major intersection of the highway linking the states of Edo and Delta.

Fatal accidents are frequent on Nigeria's poorly maintained road network.

Witnesses say many of the victims were caught up in the fire while trying to scoop petrol from the tanker which had crashed.

The fire quickly spread to some other vehicles on the highway.

A Delta state government spokesman told the BBC that the road tanker had tried to navigate a bad spot on the highway when its driver lost control.

It overturned and its content poured onto the surrounding ditches and potholes. It was while the people were scooping petrol that the explosion occurred.

Three weeks ago some 35 people were killed in northern Benue state when a road tanker exploded near their village.

A similar incident in 2012 in the south-western city of Port Harcourt killed at least 92 people including women and children who tried to scoop fuel from an overturned tanker.