Authorities in Texas said they were investigating a “major industrial accident” at an Exxon Mobil plant in Baytown, Texas.

“Some injuries have been reported. Please avoid the area,” the Harris County Sheriff’s Office said on Twitter.

Initial reports indicated some type of explosion occurred inside the plant, Sheriff Ed Gonzalez said. Four people were injured, with three taken from the scene by Lifeflight and one by ambulance, he said.

“Around 1 a.m. on 12/23/2021, a fire occurred at our facility,” Exxon Mobil Baytown Area said on Twitter. “At this time, emergency vehicles and smoke may be noticeable to the community. We are coordinating with local officials, and working to resolve the issue as soon as possible.”

Videos posted on social media showed dense smoke rising from the facility.

“My mom lives right behind the plant and around 1 a.m. I heard a loud ‘boom’ and the house shaking,” Kendall Merritt, who lives nearby, told ABC News. “The sound was as if someone had slammed a door right in my ear.”

Exxon Mobil’s Baytown complex covers 3,400 acres about 25 miles east of Houston, according to the company’s website. Its local refinery can process about 584,000 barrels of crude oil each day.

Gonzalez said on Twitter that there wasn’t an order for nearby residents to evacuate or shelter-in-place.

This is a developing story. Please check back for updates.