WASHINGTON (AFP) – Residents of a US Gulf town have been told to stay indoors and turn off their air conditioners after power failures at a nearby BP refinery and Dow Chemical plant, officials said.

Texas City Emergency Management director Bruce Clawson, raising fears of a potential blast, said the order was issued to residents after BP lost power to the entire facility at 11:00pm (0400 GMT Tuesday).

"They are taking all the hydrocarbons and flaring them so they don't blow up," he told AFP. "Not everything is burning up. Hydrocarbons are being released into the air."

He said he was not aware of anyone having been injured in the incident and expected the situation to soon be brought under control, adding that the Dow Chemical plant had been shut down safely.

At least nine tall flares could be seen from a nearby highway, according to the Galveston County Daily News, which first broke the story.

BP America said in a statement that it had "immediately" notified the city following the power failure and that no one had been injured in the incident. It added that it had initiated its own "environmental monitoring."

The same facility was the site of a deadly explosion and fire in 2005 that killed 15 workers and wounded another 170.

Last August BP agreed to pay a record 50.6-million-dollar fine for safety violations at the refinery, on top of billions in fines and compensation payouts related to that year's massive Deepwater Horizon oil spill.

BP had already paid an estimated one to two billion in civil penalties for people hurt or killed in the refinery blast and a record 50 million dollar criminal fine for environmental damage.

The Texas City facility is BP's largest refinery and has a feed capacity of approximately 460,000 barrels of crude oil per day. It processes a wide range of petroleum products, including gasoline, heavy fuel oil and sulfuric acid.