An explosion and inferno at Guinea’s main fuel depot in the capital of Conakry left at least 13 people dead and 178 injured, authorities said on Monday, as the West African country was assisted by other nations in managing the disaster.

The massive explosion sparked the fire at the Guinean Petroleum Company depot after midnight Sunday, Guinea’s presidency said. It caused significant damage in the heart of the Kaloum administrative district, home to most government offices. At least 89 of the 178 people injured have been treated and are back home, the government said in a statement. It also updated the casualty toll that Guinea’s Civil Protection Service had earlier said was provisional. Among the 13 killed were foreigners, it added.

Authorities said an investigation has started to reveal what caused the explosion at the depot that supplies most of the fuel in Guinea. The depot had been in the process of being relocated to a remote site in a bid to avoid such a disaster. There are now fears of a major supply disruption as the country relies on imported refined petroleum products.

Officials were “identifying vital fuel-related needs to prevent possible disruptions in supplies from the capital to other parts of the country”, the government said in the statement. A worker at the depot was quoted by the Conakry-based Guinee Matin news website as saying the explosion occurred while a ship was offloading. “I lost several of my friends in this fire. Some like me are guards, others are technicians. ... All offices are destroyed as well as all equipment,” said the worker identified as Ahmed Conde.

Security Minister Bachir Diallo said on state television the fire had been contained and some countries including Senegal and Mali were sending medical and safety teams. The fire razed several offices and buildings. Many residents fled their homes as thick smoke spread.

“I was sleeping when I heard a whistle, then a deafening explosion,” said resident Mounatou Balde.