After what local sheriff's deputies described as a "major industrial accident," a massive explosion was reported at an Exxon/Mobile refinery in Baytown, Texas.

According to the Harris County Sheriff's Office, four persons were hurt. One victim was in serious but stable condition, while the other three were treated for non-life-threatening injuries.

"At this time, residents may notice emergency vehicles and smoke. We are working with local officials to rectify the matter as quickly as feasible," ExxonMobil Baytown Area said in a statement.

According to ABC News, Rohan Davis, the refinery manager at the Baytown location, said he could not confirm whether an explosion occurred.

"At the moment, we're still collecting all of that data," he explained. "We will conduct an exhaustive investigation."

Baytown is located in the greater Houston metropolitan region, just east of Houston. Exxon opened its refinery in the city in 1920, and it is the company's largest in the United States.

According to its website, it produces 584,000 barrels of crude oil per day.

A second fire broke out at the site in 2019, hurting 37 people.

Residents have been warned to avoid the facility's area by the Harris County Sheriff's Office. At this time, no evacuation or shelter-in-place orders have been issued.

The Baytown Fire Department and the Houston County Sheriff's Office have been contacted for comment.