Oil rail cars ablaze after North Dakota train collision

(Reuters) - As many as a dozen oil tank cars burst into flames in eastern North Dakota on Monday after a collision with another train, state officials said, the latest in a string of incidents that have raised alarms over growing oil-rail traffic.

The incident, which has caused at least five powerful explosions just a mile outside of the small town of Casselton, occurred after a westbound train carrying soybeans derailed, and an eastbound train hauling crude oil ran into it, said Cecily Fong, the public information officer with the North Dakota Department of Emergency Services.

The last 50 oil-tank cars have been decoupled from the train, but another 56 cars remain in danger, she said. The collision destroyed both engines on the oil train. Both trains were operated by BNSF Railway Co, which is owned by Warren Buffett's Bershire Hathaway Inc.

City officials said they had heard explosions following the collision, including one as recently as 3:40 p.m. CST, more than an hour after the incident. There have been no reports of any injuries, but local residents were asked to remain indoors to avoid contact with the smoke.

The derailment occurred west of Casselton, a small town just west of Fargo, between an ethanol plant and the Casselton Reservoir, Fong said.

The incident threatens to stoke concerns about the safety of carrying increasing volumes of crude oil by rail, a trend that has its epicenter around the Bakken shale oil fields of North Dakota. Over two-thirds of the state's oil production is currently shipped by rail.

This summer, a runaway oil train derailed and exploded in the center of the Quebec town of Lac-Megantic, killing 47 people. The incident has fueled a drive for tougher standards for oil rail shipments, including potentially costly retrofits to improve the safety of tank cars that regulators have cited as being dangerously prone to puncture.

(Reporting by Jeanine Prezioso and Selam Gebrekidan, Alicia Nelson in Fargo; Editing by Gary Hill, Jonathan Leff and Bob Burgdorfer)