At least 42 people have been killed in an oil tanker explosion in Nigeria's central Niger state after the vehicle skidded off the road and crashed, spilling fuel, an aid worker has told the BBC.

Another 52 people with varying degrees of injuries are currently receiving treatment at a hospital, said Abdullahi Baba Ara, head of the Niger state emergency service.

Villagers rushed to collect fuel from the overturned tanker which suddenly exploded, setting off a massive fire that engulfed them.

Tanker explosions are a recurring tragedy in Nigeria, despite repeated warnings about the dangers of collecting spilled fuel.

The intense blaze burned many victims beyond recognition, and the injured were taken to a nearby hospital for treatment.

The accident occurred near the Essan and Badeggi communities along the Bida-Agaie road in the Katcha Local Government Area of Niger state.

Niger State Governor Mohammed Umaru Bago sent his condolences to the people, describing the incident as "worrisome, unfortunate and pathetic".

"[It] is disheartening how people have continued to approach a fallen tanker to scoop its contents" despite several awareness campaigns, said a statement by his chief press secretary Bologi Ibrahim.

The tanker, carrying petroleum products from Lagos in southern Nigeria to the north, is said to have crashed due to the bad condition of the road.

Poor road conditions are a major contributor to road accidents in the country.

In October last year, a fuel tanker explosion killed 153 people in Jigawa state, north-west Nigeria.

In January this year, a truck carrying about 60,000 litres of petrol overturned near Suleja, also in Niger state, killing at least 86 people and injuring nearly 70 others.