BLACKFALDS, Alberta—A train carrying tar sands and timber has derailed in the Canadian province of Alberta, spilling at least part of its load, officials said, though there were no reports of injuries. Officials in the city of Lacombe said one rail car released 32,000 liters (8,450 gallons) of tar oil. The Royal Canadian Mounted Police in Blackfalds said crews were working to contain Friday’s spill. Huge piles of spilled wood were visible along the tracks on Saturday and traffic was being rerouted around the area, though some residents who initially were evacuated had been allowed to return. Canadian Pacific Railway said the cause of the derailment was under investigation.