"None of the injuries is life-threatening," said Const. Anie Lemieux, a spokeswoman for the Montreal police.
Firefighters and ambulances rushed to the scene of the collision, which did not seem to leave extensive damage to the buses. One vehicle appeared to have dents in its front and a cracked windshield.
Accident investigation unit officers were trying to determine the cause of the collision between the two buses on a street in the Anjou district but Const. Yannick Ouimet said distraction could be a factor.
The buses, which were travelling westbound, were following each other at the moment of impact.
Ouimet said the first bus stopped at a stop sign and the second swerved to avoid it. Ouimet said the bright sun could have been a factor.
"The first driver might have seen the stop sign at the last minute because of the sun and so maybe braked a little rapidly," the police officer said. "The second driver was surprised at the manoeuvre and tried to avoid the accident."
He said another scenario was that the second driver was distracted, saw there was going to be a collision with the other bus and was unsuccessful at avoiding it.
Firefighters and paramedics entered the buses to check people, stacking backboards beside the vehicles until it was decided if an injured person needed to be carried to a stretcher.
Traffic was shut down in several directions while emergency crews worked.