Explosion erupts at Texas chemical refinery, injuring at least 3 people

At least three people were injured when a powerful explosion erupted at a petrochemical refinery in Texas early Wednesday morning, officials said.

Video and images taken by people in the area and posted online show a massive fireball illuminating the dark sky over the TPC Group plant in Port Neches, Texas, about 15 miles southwest of Beaumont.

The early morning explosion involved a processing unit, and emergency responders are still working to bring the fire under control, according to a press release from TPC Group.

"Teams have been dispatched to conduct air monitoring along the fence line of the facility and in surrounding neighborhoods through mutual aid," the company said in a statement Wednesday.

Three personnel on site -- two employees and a contractor -- sustained injuries in the blast and were hospitalized for treatment. All staff at the plant have since been evacuated and accounted for, according to TPC Group.

"We are focused on their quick recovery and providing support to their families," the company said. "At this time, we cannot speak to the cause of the incident or the extent of damage, but TPC is assembling a team to conduct a full and thorough investigation."

Jefferson County Judge Jeff Branick told ABC News that the plant was still on fire hours after the blast.

A mandatory evacuation was in effect for residents living within a half-mile radius of refinery. A fire department spokesperson in the neighboring city of Nederland told ABC News that evacuation orders could expand to a wider area.

A highway near the plant was shut down, and there were reports of damaged homes in the area, according to a spokesperson for the Port Neches Police Department, who expressed concern about chemicals in the air and possible secondary explosions.