Freight fireball

US authorities said late on Monday they were "strongly recommending" that the roughly 2,400 residents of Casselton leave their homes after a train carrying crude oil derailed and exploded on the outskirts of town.

The sheriff's office said that the National Weather Service was forecasting a shift in weather and winds that could send the fireball's fumes towards the town.

"That's going to put the plume right over the top of Casselton," Cass County Sheriff Paul Laney said at a news briefing.

A shelter was set up in Fargo, roughly 25 miles (40 kilometers) away.

The mile-long freight train of more than 100 cars was involved in an incident with another locomotive transporting grain - initial reports varied on the precise circumstances leading to the collision and explosion.

A spokeswoman for the BNSF Railway Co., Amy McBeth, said that the grain-laden train was the first to derail, knocking several cars from the oil train off adjoining tracks; other US media reports inverted that running order, saying the oil-carrying train derailed and was then hit by the other engine.

The series of explosions involving around 10 of the carriages, on tracks that run through the center of Casselton, caused no casualties.

Suitability of train transportation in question

The incident, one of several similar accidents in North America this year, came just weeks after North Dakota's top oil regulator estimated that 90 percent of the state's oil would be carried by train in 2014, up from 60 percent this year.

This past July, a train from North Dakota's Bakken oil patch crashed in the Quebec town of Lac-Megantic, killing 47 people. In November, another oil-carrying locomotive derailed and exploded in Alabama, causing no casualties.

msh/tj (AFP, AP, dpa)