Blast rocks oil refinery in Texas (VIDEOS)

An incident at Valero’s refinery in Port Arthur, Texas, triggered an emergency response, with witness footage showing flames and thick black smoke billowing above the facility.

Local residents described hearing a loud boom and feeling their homes shake from miles away as first responders were dispatched to the plant following reports of an explosion on Monday evening. A shelter-in-place order was issued for the west side of Port Arthur, according to local outlet 12News.

Jefferson County Sheriff Zena Stephens said authorities were responding to the incident but cautioned that it was still too early to determine whether anyone had been injured.

Antonio Mitchell of the Port Arthur Fire Department also confirmed there was an incident at the Valero facility, though he said the exact nature of it was not immediately clear as crews were still heading to the scene.

Valero’s Port Arthur refinery is one of the major refining sites on the Texas Gulf Coast with a crude oil processing capacity of up to 430,000 barrels per day.

Fuel prices in the United States were already spiking before the latest incident in Port Arthur. The American Automobile Association said the national average for a gallon of regular gasoline rose to about $3.95 on March 23, up from roughly $2.95 before the US and Israel launched their bombing campaign against Iran on February 28.