It's the third CN derailment in northern Ontario is less than a month, and the second in the same area.
Spokeswoman Emily Hamer says CN crews, including senior officers, are on the way to the scene near Gogama, Ont., about 200 kilometres north of Sudbury.
"Emergency crews are conducting a full site assessment and activating the emergency response plan with local officials," Hamer said in an email.
Provincial police have closed Highway 144 in both directions, and set up a command centre in the area.
Hamer says the crew on an eastbound freight train reported that cars derailed about 2:45 a.m. and that there are no reports of injuries.
Photos on social media show a large fireball at the site.
A CN freight train derailed on Thursday 100 kilometres east of Hornepayne but there was no leakage from the 16 residue tank cars that contained crude oil or gasoline.
And on Feb. 14, 29 cars of a CN freight train carrying crude oil derailed in a remote, wooded area about 80 kilometres south of Timmins, Ont., with seven catching fire.
There were no injuries in those two derailments.
Also on HuffPost