GARYVILLE - Several workers were injured in a powerful explosion at the Marathon Petroleum refinery in St. John the Baptist Parish on Monday, the company said in a statement released later that night. 

Initial reports from Marathon said that no one was hurt, though a company spokesperson issued a news release late Monday saying that a total of six contract workers suffered injuries. 

"On Monday, Feb. 21, Marathon Petroleum emergency responders extinguished a fire at the company’s Garyville, Louisiana, refinery that had begun at approximately 9:30 a.m. Central Time. All employees and contract workers were accounted for. Six contract workers sustained minor injuries, three of whom were treated on-site. Three were evaluated at a local healthcare facility as a precaution and were released. Air monitoring was deployed in the community, and no hazardous levels of emissions were detected. Air monitoring continued through the night as a precaution. The safety of responders, employees, contractors, and the community are our top priority, and we will conduct a full investigation to determine the cause of the fire."

Witnesses near the Garyville facility reported hearing a loud boom some time after 9 a.m., adding that "everything shook" from the shockwave. One resident heard the explosion from about five miles away in Laplace. 

"My wife and family was still in the house, and they came outside to see what was going on," Leonce Aydell said.

Video posted on social media showed a large fire at the facility.

According to St. John Parish President Jaclyn Hotard, there is no off-site threat to the rest of the community at this time. 

The cause of the explosion remains under investigation.