BILLINGS, Mont. (AP) — Exxon Mobil officials say a fire broke out at a processing unit in the company's Lockwood refinery.

Exxon spokeswoman Pam Malek says the fire was reported at 10:30 a.m. Sunday.

The refinery's fire brigade responded and crews extinguished the blaze in about two hours.

No injuries were reported.

The cause is under investigation.