Footage of the fireball exploding into the air has been posted on social media.

The Nederland Volunteer Fire Department’s wrote on Facebook that there is a mandatory evacuation for everyone within half a mile of the plant.

“This could change and expand to a greater area, so please pay attention to your local news station as this situation develops since we may not be able to keep this page updated this morning,” the department said.

People have described feeling the effects of the explosion from miles away, including in neighboring Louisiana.

“I noticed a yellow light lighting up the sky through the window out of the corner of my eye at first. When I opened my blinds to see, all of a sudden the sound of an explosion came,” Casey Porter told Newsweek.

“I have never felt anything like it before. It knocked me out of my bed and it felt like a train was tearing through our house,” added Eddie Ramierez.

Crystal Holmes, Captain at the Jefferson County Sheriff’s office, told Reuters that they were “able to pull two injured employees out” following the explosion, adding there could be more.

“There is search and rescue inside the plant but there is also damage to nearby homes so we’ll be going door-to-door checking on these people and their homes,” Holmes added.

However, there are conflicting reports on how many injuries there has been, with some saying the number is still zero.

“Just letting everyone know we’re okay, made it out of the area (staying with fam) after a refinery exploded a few blocks from our apt. Broke our window & shook our entire complex,” Twitter user @SpicyGamerChic wrote. “Immediately left knowing the hazards of the possibility of toxic gases being released.”

Fellow Twitter user @evalegendre12 added: “The plant by our house in Port Neches is on fire and an explosion went off like a BOMB and literally made our walls flex. Literally thought we were about to die.”

According to Reuters, the initial explosion was followed by secondary blasts. Firefighters are currently working to extinguish the huge flames at the plant.

According to its website, the Port Neches plant can produce more than 900 million pounds of chemicals. It also employs more than 175 full-time employees and 50 contractors.

This is a developing story and will be updated as more information becomes available.