State police say three workers have died from an explosion and fire at a natural gas facility along a small highway near the oil and gas city of Houma.

State police Trooper Evan Harrell said the bodies of three workers were found following Thursday's explosion. He says two other workers were seriously injured.

The explosion erupted about 11 a.m. at a facility owned by the Transcontinental Gas Pipeline Co., a subsidiary of Williams Partners, a major natural gas supplier.

The cause of the explosion is under investigation.

Williams Partners says the workers killed and injured were contractors doing maintenance work when the explosion occurred.

The company says its workers were unharmed.

Black smoke billowed from the facility hours after the explosion. Officials said the smoke posed no health risks.