UPDATE: Transportation Safety Board investigation underway into collision between two planes

TORONTO – The Transportation Safety Board says it's investigating after two passenger planes collided on the ground at Toronto's Pearson International Airport on Friday evening.

No passengers or crew were hurt, but Beverly MacDonald, a spokesperson for the Greater Toronto Airports Authority, said an airport firefighter was hospitalized with unspecified injuries.

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.

Witnesses took to Twitter to share pictures of firefighters working around the tail section of the damaged aircraft.