CN Rail is investigating why three tank cars carrying crude oil derailed Thursday night in Winnipeg.

It happened at about 9 p.m. in Symington Yards.

The cars came off the tracks but remained upright.

"Our CN crews did respond to the scene and two of the tank cars have since been rerailed," said CN Rail spokesman Warren Chandler.

No one was hurt in the incident and there were no leaks, he said.