At least 118 inmates escaped from prison after heavy rain damaged the facility
Mustapha Habib Ahmed, the head of the National Emergency Management Agency said the gas cylinder was in a welding shop when it exploded, killing nine people.
Emergency responders pulled bodies from the rubble during a search and rescue operation.
At a nearby school, parents rushed to remove their children after hearing news of the blast, witnesses said. There were no reported injuries among the school children.