A fire in northern Honduras has left at least 377 prisoners dead, authorities said, as inmates accused guards of leaving them locked in their cells.

Most of the victims suffocated to death in the fire, which broke out at a prison in Comayagua this week.

The possibility of arson by an inmate who escaped was being investigated. Earlier reports blamed the fire on a prison mutiny.

The medium-security prison, built for 450 prisoners, had about 820 occupants. Scores were being treated for burns and other injuries. A total of 475 prisoners had been transferred to secure locations, said Security Minister Pompeyo Bonilla.

Identifying the dead would take about three days, said Lucy Marrder, chief of forensic medicine at the Ministry of Justice. The inmates accused guards of not opening cell doors during the fire.

"We were burning, panicking, particularly since they would not open the cells," a prisoner said from hospital.