Montreal train explosion
© Steve Poulin/QMI Agency
A train transporting crude oil derailed and exploded early Saturday morning in a town three hours east of Montreal, forcing the evacuation of the town's downtown and flooding a river with crude.

It was unclear Saturday morning if there were any injuries in the town of Lac-Megantic, about 300 km east of Montreal.

Seventy-three train wagons derailed - each carrying 100 tons of crude oil, Christian Blanchet, a spokeswoman from the local environment authority, said.

Blanchet said the explosions destroyed one wagon and three others caught fire, and that crude oil spilled into the Chaudiere River.

Authorities forced about 1,000 residents from their homes Saturday morning and about 4,000 homes were without electricity. A thick plume of smoke could be seen over parts of the town after the derailment, and witnesses told QMI Agency they heard at least six explosions.

Police cordoned off parts of the town and the security perimeter could be extended if investigators who are on site to test the air quality determine that the air is unsafe.

The town's residents took to social media Saturday morning to locate family members, and a Facebook page was created to help citizens find those still missing.

Over 100 firefighters tried to control the fires Saturday morning, and firefighters from across the border in the U.S. were also called to help.

The train was owned by Montreal Maine and Atlantic Railway (MMA), a company that specializes transporting chemical products and crude oil. MMA transports products by train throughout Quebec, Vermont and Maine.

It is still unclear what caused the derailment.