A 14-year-old boy has been charged, and two other teenagers are still being sought by police after a TTC bus operator was stabbed in North York Wednesday.

It happened in the area of Keele Street and Ingram Drive just before 1 p.m.

Toronto police said a group of young men boarded a TTC bus and became involved in an argument with the driver.

After pulling over, police said, the altercation continued outside the bus, where the suspects allegedly attacked the driver and stabbed him multiple times.

The driver sustained serious injuries and was taken to the hospital. Police said he is expected to make a full recovery.

On Thursday, police announced that a 14-year-old Toronto boy was arrested and charged with aggravated assault.

Two Black male suspects between the ages of 15 and 17 remain outstanding, police said.

The first one has a thin build, stands five-foot-six and was wearing dark clothing. The other has a medium build, stands five-foot-seven and was wearing a dark blue winter jacket.

Police are asking anyone with information to contact them at 416-808-1200 or Crime Stoppers anonymously at 416-222-TIPS (8477).

The incident happened just a week after another TTC worker was stabbed at Dupont Station, prompting the head of a transit union to demand Thursday immediate action from all levels of government to protect transit workers.

“Thousands of assaults are reported annually in this country and thousands more go unreported, leaving transit workers vulnerable with little or no protections,” ATU Canada President John Di Nino said in a statement.

“This is why once again we are calling for the immediate need and interventions of governments, employers and lawmakers to take action.”

Di Nino is concerned about the long-term effects of the violent incidents on transit workers, and that’s why he said more needs to be done to prevent them from happening.

“The latest incident at the TTC reminds us of the major factor of assaults and that is fare disputes, which can be easily remedied in a fare-free system, for example,” Di Nino said.

“ATU Canada calls for and to be partner in a national task force to be implemented to address these issue and report back with recommendations for transit agencies to adopt.”