HELENA, Mont. — More than two dozen cars of a BNSF Railway Co. freight train hauling coal from the Powder River Basin in Wyoming to Minnesota have derailed in eastern Montana, spilling some of the load.

BNSF spokesman Matt Jones said 29 cars toward the end of the 115-car train derailed just east of Terry at about 9 p.m. Monday. The rail line remained blocked at mid-day Tuesday.

Jones did not know how much coal was spilled, but said all 29 derailed cars tipped over and spilled some of their load. The cars hold an average of about 120 tons of coal each.

The cause of the derailment is still under investigation.