(Stations: UPDATES with oil prices rising on news of explosion) BILLINGS, Mont. (AP) An explosion at the Exxon Mobil refinery in Billings this morning, briefly sent oil prices back above 88 dollars a barrel.

News of the explosion exacerbated growing concerns about the adequacy of crude oil supplies.

But prices fell to about $87.30 a barrel after the government reported a larger than expected increase in overall crude and gasoline inventories.

This morning's blast happened when hydrocarbon gas leaked from a high-pressure pipeline and was ignited.

A large explosion and fireball followed. Exxon Mobil officials say no one was hurt and the fire was under control about 20 minutes after it started.

(Copyright 2007 by The Associated Press. All Rights Reserved.) APNP 10-17-07 1009CDT | save this article / add to your favorites list