An on-duty TTC bus driver has been charged with careless driving after allegedly slamming on the breaks to avoid a collision Thursday morning.

The driver, who police have not publicly identified, had been changing lanes near Bay and Wellesley streets at around 9 a.m. when it happened.

Nine people were taken to hospital with minor injuries following the incident.

Sgt. Brian Maslowski told CP24 that most people just had "bumps and bruises."

About 45 to 60 people were on the bus at the time.

"I just felt the bus suddenly break and then all of a sudden it was just people flying," Arlene Davis, who was onboard at the time, told CP24. "People were screaming and yelling and just trying to help each other."

Davis said that she believes an overcrowded bus could have triggered the incident, however TTC spokesperson Danny Nicholson told CP24 that the number of people on the bus was not unusual for that time of day.

"Obviously at that time of day, people will be standing, but there is not an overcrowding issue on that bus line," he said.

Police have ruled out alcohol as a factor.