NEW YORK (Reuters) - A fire broke out at United Refining Co.’s 70,000-barrel-a-day oil refinery in Warren, Pennsylvania, the local fire department said on Sunday.

Fire officials responded to the refinery just after 6 p.m. on Sunday, but were on standby as the plant’s internal fire crew responded to the blaze.

The fire department did not have any details on what caused the fire, whether it had been extinguished or whether refinery operations were affected, said Captain G. Danielson, who declined to give his first name.

The plant staff were not immediately available to comment outside of business hours.

The plant is operated by United Refining Company, an independent refiner and marketer of petroleum products.