Updated

A Vietnamese official says six workers have been killed in a fire in an underground coal tunnel in the country's north.

Duong Quang Lai, director of the Uong Bi Coal Co. in Quang Ninh province, says the bodies of the workers who died of suffocation were pulled out Thursday morning.

One worker escapes with burns after the fire erupted Wednesday night.

Authorities are still trying to put out the fire at the tunnel, which is between 30-105 meters (98-345 feet) deep.

An investigation is underway.

The province is Vietnam's main coal-mining region. Dozens of workers have been killed in the past decade in mining accidents there.