TORONTO -- Multiple fatalities were reported in a fiery multi-vehicle crash Friday night on Highway 400 in north Toronto.

Ontario Provincial Police Sgt. Kerry Schmidt says there were at least four fatalities, but there could be more. He said police believe that at least one of the dead was a child.

He added that investigators were still working with the coroner to confirm the number of fatalities.

Schmidt said the crash happened in the highway's southbound lanes shortly before 10 p.m. ET and involved three transport trucks along with several other vehicles, some of which suffered massive damage.

"These vehicles are completely unrecognizable," he said. "I think this is one of the most incredible scenes I've ever been to in terms of the number of fatalities and just the trauma that's been sustained and the way these vehicles ended up."

Schmidt said one of the truck trailers and several vehicles were gutted by a fire that was ignited by the crash.

An OPP news release issued early Saturday confirmed that a total of 12 vehicles were involved in the pileup, and it said the identities of those killed were being withheld pending notification of their next of kin.

Along with the fatalities, the release said that two people were taken to hospital with non-life threatening injuries, while several others sustained minor injuries and remained at the scene.

There was no early word on a possible cause for the horrific accident, though Schmidt noted the weather and road conditions were both good, and there was no highway construction underway at the crash site.

He expected the OPP's collision reconstruction team would remain at the scene well into Saturday morning.

All lanes on the busy thoroughfare were open by Saturday afternoon.