A 105-car freight train hauling potentially toxic refrigerant derailed before dawn Wednesday, forcing the evacuation of several dozen residents and closing roads north of Sacramento.

There were no reported injuries, but 23 cars left the tracks in the 4:55 a.m. derailment, said Jim Loveland, a spokesman in Southern Pacific's San Francisco office. The cause of the accident was not clear."The track is blocked in both directions," Loveland said. "The cars are in a general pile-up with an accordian effect.

"It was a freight train between Ogden, Utah, and Oakland with 74 loaded cars and 31 empties. The cars that derailed carried general merchandise, including scrap metal. There was also a tank car that is leaking."