The TTC says it's investigating after one of its bus drivers was caught on camera playing a mobile phone game while behind the wheel.

A passenger captured the video and sent it to CBC Toronto. That person declined to be interviewed, but said in an email the incident took place on the Sherbourne Street route during the tail end of Wednesday morning's commute.

In the one-minute video, you can see the bus moving while the driver plays the game and quickly clears ads that pop up. Early in the video, you can hear an emergency vehicle's sirens in the background.

Watch: You can see the video for yourself below.

The transit agency says it's looking into the incident 1:03

CBC Toronto's audience was quick to point out the driver was likely playing Toon Blast, a free puzzle game.

TTC spokesperson Stuart Green said the agency is aware of the video.

"We will be taking appropriate action," Green said in an email.

"Our expectation is that operators drive safely and follow the rules of the road at all times."