The city is investigating after photos surfaced online yesterday that appear to show an HSR bus driver grabbing a passenger by her hair.

"We are aware of the incident that took place yesterday between an HSR Operator and one of our customers and are currently investigating the matter," said city spokesperson Jasmine Graham in an email.

Fellow passenger Sierra Johnson watched the incident unfold, and posted the photo on Facebook that has been widely shared.

If you're going to get aggravated like that, you shouldn't be working for the city. - Sierra Johnson, HSR rider

Johnson told CBC News that it happened when she was trying to take her young son to the doctor yesterday on the route 23 Upper Gage bus.

She says the driver, who has not been named, gave her and the woman standing in front of her a hard time for not having photo identification with their student bus passes.

Johnson got on after putting in an extra 30 cents in the fare box, while the woman in front of her got on after putting in another bus ticket, she says.

Then, she alleges, things escalated.

"She started giving me a hard time for standing on the bus," Johnson said. "Then she told me to get off my effing phone." Johnson says she was calling to complain to HSR at the time.

The city says it is investigating the incident. (Sierra Johnson/Facebook)

As things continued, the driver was agitated and missed an older woman's stop, Johnson says. She then stopped the bus and got off to use her phone.

That's when the other woman got off and confronted her, saying she was going to be late for work, Johnson says.

"That's when the bus driver pulled her hair," Johnson said. "It was out of anger. She was trying to whip her around.

CBC asked to speak with the woman in the photo, but Johnson said she was declining interviews right now.

"The whole thing made me feel like I have no trust in the HSR," Johnson said.

"If you're going to get aggravated like that, you shouldn't be working for the city."

Hamilton police say that no one has come forward to press charges related to the incident.

Marissa Mcconnell says she boarded the bus behind the two women, and saw the interaction with the driver. She backed up Johnson's account of what happened.

"Yes maybe the young girl was a bit snippy with the bus driver, but for good reason," Mcconnell said.

"A bus ride that usually take about 25 minutes turned into a hour and 15 minutes," she said. "Overall, what that bus driver did was wrong."

adam.carter@cbc.ca