UPDATE: Officials from Montana Rail Link said Tuesday they are working on cleaning up the site of a coal train derailment on Sunday night.

MRL officials said they estimated "that very little material mad its way into the Clark Fork River."

They said the clean up process could take several weeks to complete, but expected to reopen the main line Tuesday.

Original story:

NOXON, Mont. - A Montana Rail Link Official has confirmed that approximately 30 coal cars derailed Sunday night in Northwest Montana.

Jim Lewis with Montana Rail Link said there are no reported injuries and the train was not hauling hazardous materials. Coal spilled out of several of the cars.

Lewis said the cause of the derailment is under investigation.