There was tension in the early hours of Wednesday as fire gutted the West African Examinations Council building in Yaba area of Lagos State.
Many people are feared trapped in the building as the fire rages.
The cause of the fire is yet to be ascertained.
However, emergency responders are at the scene and the fire is being put off.
Sources said the inferno was caused by power surge in one of the offices, which immediately went wild.
Smoke was earlier seen oozing at the top of the high-rise building as the fire was burning within its office rooms.