HELENA, Mont. (AP) — A BNSF Railway official says a cargo train has derailed on a main rail line running across the Northwest.

BNSF spokesman Gus Melonas (mel-OWN'-us) says that there are no injuries and no environmental threat from Thursday morning's derailment near Saco in northeastern Montana.

The rail line was closed as crews worked to repair the track. Melonas says the line was expected to reopen as early as 10 p.m. Thursday.

The train was headed from Minneapolis to Spokane, Wash. Eight empty cars derailed, with seven toppling over an embankment.

Melonas says rail officials don't know what caused the derailment.