Concerns about an overturned propane tank led to the precautionary evacuation of an area around a train derailment north of Toronto on Wednesday.

The derailment occurred as a Toronto-bound train passed outside Buckskin, Ont., near Severn Falls, shortly before 3:30 a.m.

Kevin Hrysak, a spokesperson for CP Rail, said 21 of the 62 cars the train was carrying derailed, spilling from the tracks. Some of the derailed cars struck a train stopped on an adjacent track.

Officials say there were no injuries and nothing hazardous spilled in the crash. But there were concerns about an overturned train car carrying propane.

About 30 residents who were evacuated from the area were likely to spend Wednesday night out of their homes as crews worked on the scene.

OPP Const. Gerry Dwyer said that the cleanup was moving ahead with caution, as to not damage the tank further.

"The propone tank is on its side. At this point in time it is not leaking, that we can see," Dwyer told CTV Toronto.

"Right now that is the key car. I understand that some of the cars that are carrying the other dangerous items are still upright."

The clean up could take several days as crews work to take care of the mess from the derailment.

The Township of Severn has evacuated residents within an 800-metre radius of the crash as a precaution. The Coldwater Community Centre in nearby Coldwater has been established as an emergency shelter.

The evacuation affected about a dozen homes.

CP Rail representative were on site Wednesday to oversee the cleanup. The company said it was too soon to determine what caused the derailment.

Upper Big Chute Road has been closed to the public until the situation has been resolved. CP Rail expects the area to reopen later Wednesday.

The site is not far from the scene of a 2006 derailment, when a train carrying steel slipped from the tracks while rounding a turn. The cause was later determined to be a faulty wheel sets and prompted a massive recall.

With a report from CTV Toronto's John Musselman