A freight train hauling dozens of cars of molten sulfur derailed, spilling some of its cargo onto the ground and releasing an eggy smell into the air, authorities said. There were no reports of any injuries or evacuations.

The three-locomotive, 68-car train derailed late Friday, Littleton Police Lt. Mike Broadhead said. The cause of the derailment was not immediately determined.

The northbound train, operated by BNSF, derailed just east of downtown Littleton, a suburb south of Denver.

At least 17 cars came off the tracks and several lay on their side in an accordian-like jumble, BNSF spokesman Gus Melonas said. It appeared that sulfur had spilled from fewer than five of the derailed cars.

Several spot fires broke out but were quickly extinguished.

The rotten-egg odor of sulfur could be smelled in places up to a quarter mile away, Broadhead said.