Authorities in Texas are saying that a "major industrial accident" occurred in or near an ExxonMobil refinery in Baytown, near Houston on Thursday morning. At least four people are known to be injured at present, and no deaths have yet been reported.
According to KHOU-TV in Houston, the explosion occurred in a part of the refinery that is used for processing gasoline. The explosion caused a massive fire that was witnessed and recorded by local TV news crews and social media users.
Harris County Sheriff Ed Gonzalez tweeted that the fire appeared to have been the result of an explosion inside the plant and that there did not appear to be any need to evacuate the area.
Police say that the fire initially broke out around 1am local time, and fire crews were continuing to battle the blaze at the time of this reporting. All four of the injured workers were reported to be in "stable" condition in Houston hospitals.
The cause of the fire remains unknown at this time. A spokesperson for ExxonMobil said that "Our Industrial Hygiene staff continues air quality monitoring at the site and fence line. Available information shows no adverse impact at this time," and additionally that the company is cooperating with authorities "as appropriate."
The Baytown ExxonMobil complex is the second-largest oil refinery in the United States.
This is a developing story which may be updated as events warrant.