A large explosion has ripped through the cargo wing at the airport in Nigeria's main city, Lagos.

Witnesses said a loud blast was followed by a huge fire that quickly consumed a two-story cargo facility at Lagos' busy Murtala Muhamad International Airport.

Firefighters battled the flames, as ambulances raced to and from the scene for several hours after the blast. Residents of Lagos said a large plume of smoke could be seen from many kilometers away.

Witnesses at the airport said they saw rescue crews pulling bodies from the burning building. A number of people were believed to be trapped inside the normally busy cargo wing, which houses offices of cargo companies and others.

Nigerian authorities gave no immediate explanation for the blast.

Preliminary accounts from witnesses indicated the explosion was accidental.