TORONTO -- The Transportation Safety Board's investigation into a collision between two planes will examine whether a major airline followed its evacuation protocols, a spokesman said Saturday.

Officials say an empty Sunwing plane that was being towed struck a WestJet aircraft, which was carrying 168 passengers and six crew members, while both planes were on the tarmac at Toronto's Pearson International Airport on Friday evening.

A spokeswoman for WestJet said everybody was safely evacuated from the plane via emergency slides and nobody on board was injured.

But passengers have offered accounts of confusion aboard the plane and allegations that procedures were not clearly communicated.

WestJet did not respond to questions about the allegations, but Transportation Safety Board spokesman Chris Krepski said they will be one of the aspects examined in its pending probe.

"Certainly we would look into the evacuation procedures," he said in an interview. "We would look at the procedures in place at the Toronto Pearson Airport with respect to ground handling operations. ... These are all elements of information we will be gathering as part of the investigation."

Ali Alagheband, an engineer from Toronto travelling aboard the Westjet flight with his wife and son, said chaos erupted shortly after the plane touched down early Friday night.

He said the flight from Mexico had landed early, requiring the aircraft to wait on the ground before passengers could disembark.

As they waited to taxi to the gate, Alagheband said he felt what he called a "significant vibration" that led him to believe the plane had been hit.

Shortly thereafter, he said he saw a fireball near the plane's wing and began to smell smoke.

He said the resulting commotion made it difficult to hear instructions from the flight crew, adding what information came through was sometimes contradictory.

But he said the crew's primary piece of advice was at odds with what he felt to be the safest approach.

"I'm sure they did their best, but ... they kept saying 'be seated, remain seated' as the fire was going on outside," he said. "I was telling my wife, 'to hell with keeping seated, we've got to get out of here."'

Alagheband said he never heard announcements coming from the pilot clarifying how to proceed, a situation he said was dangerous given the fact that a fire was burning near an area where plane fuel is stored.

The Greater Toronto Airports Authority said crews extinguished a small fire on the Sunwing plane and some flight operations were affected by the incident. One airport firefighter was sent to hospital with undisclosed injuries.

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.