A tank of sulfur caught fire Monday at a refinery and residents were urged to take precautions against the fumes, authorities said.

The minor fire at the Valero Houston Refinery was extinguished and the fumes were contained, said Valero Energy Corp. spokesman Bill Day.

Residents were urged to remain indoors for several hours or go to a shelter to wait out the fumes. Day said officials didn’t believe the fire posed any further threat to the community.

Five workers were taken to a hospital for checkups and released, Day said.

The cause of the fire was not immediately determined.

The refinery produces gasoline and gas derivatives.