Officials in Nigeria say a series of explosions that have shaken the commercial capital, Lagos, are the result of a fire at a munitions depot. Authorities fear there may be a high number of casualties, since the explosions happened in a densely populated area just outside the city.

The explosions caused panic in some sections of Lagos, prompting Nigerian officials to go on state television and radio to explain the incident.

Officials say the blasts erupted when fire spread through a military facility in the outlying Ikeja district of Lagos, near the city's airport. Witnesses say the explosions were so strong they shook buildings in the vicinity and echoed throughout the city.

Reports from the scene say the fire started in a market before it spread to the adjacent military facility.

The commander of the facility, Major General John Anda, spoke on state television Sunday, assuring viewers that the explosions were purely an accident and did not have, he said, any political implications whatsoever.

The commander said fire engulfed the aging ammunition depot, where a large amount of high-powered explosives are stored. He said military officials had been discussing efforts to modernize the facility before the blasts occurred.

Officials on Sunday warned residents that explosions would be heard for several hours, as fire continued to spread through the armory. Residents living in the neighborhood around the Ikeja facility were evacuated, as shrapnel from the explosions blew across the area.

The sound of the explosions on Sunday night raised tensions among people in Nigeria, a country that has experienced six military coups since it achieved its independence from Britain in 1960.