WELLS, Nev. (KLIX) – A freight train derailed on Wednesday morning near Interstate 80 about three miles east of Well, Nev., according to the Nevada Highway Patrol.

It is unknown at this time what caused the derailment, but responders were still at the scene Wednesday afternoon and the incident is being investigated.

The Elko County Sheriff’s Office said the Union Pacific Railroad train had 22 cars, one which was carrying a shipment of vegetable oil that spilled during the derailment. Some rail cars also were carrying munitions, but the sheriff’s office said they were “located at the opposite end of the train, away from the derailment.”

I-80 was closed for a period of time, but authorities said it has since reopened.

They said a white powdery substance was identified at the site as aluminum oxide, and anyone in contact with it should wash it off immediately.

Wells is about 115 miles south of Twin Falls.