A plume of black smoke near Houston's Ship Channel that was visible from miles away originated at Exxon Mobil Corp.'s (NYSE: XOM) Baytown, Texas, facility according to the Coast Guard's Vessel Traffic Service.

Reuters reported that there is a fire at the facility, and that ExxonMobil would issue a statement shortly. Emergency management officials had no immediate comment.

The facility comprises a chemical plant and a 560,500 barrels per day (bbl/d) oil refinery.

In a separate article April 7, Reuters reported that the refinery--the country's second largest--has begun increasing production levels for the first time since cutting back in early February due to a glut of domestic gasoline, according to sources familiar with plant operations.

The 560,500 bbl/d refinery's crude oil intake was cut between by 75 Mbbl/d below faceplate capacity and 100 Mbbl/d below normal production levels in early February.