At least 25 people have been killed after a tourist bus collided with a truck in Bahia state in northeastern Brazil, state firefighters said Monday.

"Military firefighters responded to an incident that left 25 dead" near the municipality of Gaviao, about 155 miles (250 kilometers) from the capital of Bahia state, Salvador.

Five people were also injured in the accident Sunday night, according to Brazilian press reports, which also published images of the twisted fuselage of the truck.

The cause of the accident is still unknown. The bodies of the victims have been handed over to police for identification, the firefighters said.

The mayor's office of Jacobina, a city close to the accident, declared three days of official mourning on Monday and is preparing a "collective wake" for the victims.