An oil refinery explosion in southeast Nigeria on Friday (April 22) left at least 100 people — including women and children — dead, CNN reports.

State officials told the outlet that the explosion at the oil-rich Ohaji-Egbema local government area in Imo state was set off by a fire at two fuel storage areas where over 100 people worked.

Local officials described a scene where several workers were caught in the explosion as others attempted to flee the fire by running into nearby wooded areas.

The IMO Commissioner for Petroleum Resources Goodluck Opiah told the Associated Press the death toll is within “the range of 100.”

“A lot of them ran into the bush with burns and they died there,” he said.

The Imo State Commissioner for Information Declan Emelumba mentioned that a mass gravesite is being planned for the victims of the explosion. Many of them were “burnt beyond recognition,” Emelumba said.

Officials have started to fumigate the area and a search is underway for suspects. “There are no arrests yet but the two culprits are on the run with the police now looking for them,” Emelumba said.

Nigeria, which is Africa’s richest country and the largest crude oil producer, lost at least $3 billion worth of crude oil between January 2021 and February 2022, according to AP.

The refinery that blew up in Imo is believed to have been an illegal operation established by business owners looking to avoid government regulations. Militants have a history of targeting and blowing up oil pipelines — especially in areas such as the Niger Delta region.

Nigeria’s Defense Department announced in early April it had created a task force to prevent crude oil theft. Within the past two weeks, up to 30 illegal oil refineries were shut down in the Niger Delta region, the Nigerian Defense Department announced.

In a statement, Nigerian President Muhammadu Buhari called the explosion a “catastrophe and a national disaster.”