A blaze inside a Louisiana refinery that turned the night sky a shade of orange and sent a large plume of smoke into the air over Baton Rouge has been extinguished, ExxonMobil officials say.

The fire erupted at the facility in Baton Rouge around 11:30 p.m. Tuesday, Baton Rouge Fire Department spokesman Curt Monte told reporters. No injuries were reported, he said.

“We’ve seen reports of people saying explosion. I can tell you there was no explosion,” Monte told reporters at an early morning news conference Wednesday.

“We want the people to know that there has not been any off-site impact and we’re going to continue to be out here as long as it takes to make sure that that doesn’t happen,” he added.

ExxonMobil has been working with the fire department’s hazardous materials unit to monitor air quality in the area, company spokeswoman Megan Manchester told reporters shortly after dawn Wednesday. Results so far have been “below detectable limits,” she said.

The fire was contained to the location where it started, Monte said. The glow of the fire could be seen from miles away, news outlets reported.

It wasn’t immediately clear what caused the fire.

“Once deemed safe, our teams will go in to conduct a thorough investigation to determine the root cause of this incident and how we can learn from it,” Manchester said.

“Our response teams did exactly what they’re highly trained to do. They responded, they responded very quickly, so we’re very thankful for that,” she added.

ExxonMobil is the largest manufacturing employer in Louisiana and its Baton Rouge refinery is the fifth largest in the country, WAFB-TV reported. It produces gasoline, jet fuel and more, as well as items such as paint and adhesives at the chemical plant.

The company said in a tweet that it was responding the situation, including monitoring air quality at the fence line. The air outside the plant “bore no particular odor,” The Advocate reported.

Baton Rouge, Louisiana’s state capital, is about 80 miles (129 kilometers) northwest of New Orleans.

(AP)