Authorities in the West African nation of Niger say at least 55 people are dead after a tanker truck filled with fuel exploded near the country's main airport.

President Issoufou Mahamadou called the explosion a "national tragedy" after visiting a hospital where dozens were wounded, some with serious burns. The death toll was expected to rise as doctors said some were in critical condition.

Authorities believe the explosion took place after the tanker truck flipped over near a gas station. A crowd of people came to try and collect the fuel that leaked out as a result of the accident.

Scores of people have died in similar accidents in West Africa as impoverished people risk their lives to collect fuel leaking from pipelines or trucks.