The Toronto Transit Commission is investigating a report that a dog was fatally struck by a bus earlier this week.

The incident allegedly happened Monday morning in Toronto's Leaside neighbourhood. Witness Kristin Gaziuk told CP24 on Wednesday that she saw an elderly pet owner walking her dog in the area of Millwood Road and McRae Drive at approximately 8:30 a.m. when the animal was struck.

She said the TTC bus didn't stop after the dog was hit, and its owner was "hysterical" when she realized the animal was dead. Gaziuk said she and her boyfriend called police and the TTC to report the alleged incident.

TTC spokesperson Brad Ross said they received an anonymous call about the "very said incident" and a probe has been launched.

Ross said they haven't been able to track down the bus that allegedly hit the dog, but said drivers are required to remain on the scene if an animal is struck.

He added that depending on the size of the dog, the driver may not have been aware that the bus hit the animal.