OC Transpo promised an investigation into at least two cases of its drivers appearing to use cellphones to send text messages while behind the wheel.

The public transit authority asked anyone who spotted drivers using phones while driving to contact them immediately.

"OC Transpo does not tolerate texting while driving," OC Transpo said in a Thursday evening new release, adding anyone who breaks the law will be disciplined and possibly dismissed.

The investigation comes after two bus drivers were seen using their cellphones while driving. One picture — taken last fall but given to the Ottawa Citizen this week — shows a female bus driver text messaging while driving.

Another video given to CBC News shows a driver repeatedly checking a phone between his legs.

The passenger who shot the video said they began filming after hearing another vehicle beep and seeing the bus go through a red light.

Alain Mercier, OC Tranpo's general manager, would not comment directly to CBC News.

The Amalgamated Transit Union, which represents drivers, said it in no way condones drivers using cellphones on the job.

City transit commission called for investigation

Coun. Diane Deans, chair of Ottawa's new transit commission, called for an investigation Thursday morning.

"There will be an investigation, and if there is an appearance that a law was broken — be it a bylaw or a provincial law — then we will refer it to the Ottawa police," Deans said.

Texting behind the wheel has been banned in Ontario since October 2009, but Deans said OC Transpo had internal regulations that prohibited the use of cellphones while operating vehicles even before that.

"We have a broader policy that's been in place since 2004 which limited the use of cellphone devices," Deans said.

OC Transpo drivers are allowed to use handheld devices during rest stops, when the vehicle is not in operation.

The controversy comes ahead of contract negotiations between the city and union.

Toronto transit reportedly fires texting drivers

The Toronto Transit Commission reportedly fired three employees who were caught text messaging behind the wheel earlier this week.

Ontario's law against texting while driving has been enforced for about one year. A driver caught in the act is subject to a fine of $155. Anyone challenging the ticket may have the fine lowered to $50 or raised to $500 at the judge's discretion.