UPDATE: Passengers evacuated after planes make contact on Pearson's tarmac

An update into the Transportation Safety Board investigation into two passenger planes that collided on the ground at Toronto's Pearson International Airport on Friday evening.

TSB spokesperson Chris Krepski tells Newstalk 1010 they are still investigating, but have found the fire started "when an auxiliary power unit of the Sunwing flight made contact with the Westjet flight."

Krepski says investigators continue to interview flight crew members and they have the flight data recorder and cockpit voice recorder.

No passengers or crew were hurt, but Beverly MacDonald, a spokesperson for the Greater Toronto Airports Authority, said an airport firefighter was taken to hospital, treated and released.

WestJet said one of its flights, inbound from Cancun, Mexico, with 168 passengers and a crew of six, was stationary and waiting to go to a gate when it was struck by a Sunwing aircraft moving back from a gate.

Spokeswoman Lauren Stewart said the WestJet passengers were evacuated from the Boeing 737-800 via emergency slides and all were safely in the terminal and clearing customs shortly after the collision.

Sunwing said there were no crew or passengers aboard its aircraft, which was being towed by the airline's ground handling service at the time of the incident.

The Greater Toronto Airports Authority said crews extinguished a small fire on the Sunwing plane and some flight operations were affected by the incident.