Two teenagers have been arrested following an assault on a Winnipeg Transit bus.

It happened Wednesday afternoon during the rush hour commute after a passenger got on board with a knife.

The incident led to an abrupt stop downtown for the bus which was carrying around 50 passengers.

“When I found out there was a knife, it was a bit scary,” said Haley Musick who was on the bus.

Winnipeg police said another passenger noticed the knife and took matters into his own hands.

"So another male passenger on the bus, when the male sat down, took the knife from him and gave it to the bus driver," said Const. Tammy Skrabek.

Officers said a teenage boy became agitated when the man took his knife away and ended up in a struggle with the passenger who intervened.

The driver notified police around 4:45 p.m., stopped the bus in the area of York Avenue and Osborne Street and asked everyone to get off.

"When police arrived the struggle was still continuing,” said Skrabek. “They observed a youth male sort of being held down by the passenger but a female attacking the male who was trying to assist."

Police said a 17-year-old boy and 15-year-old girl who were intoxicated were arrested and have been charged with numerous offences, including assault. Police had said Wednesday officers used a Taser to prevent the boy from becoming a danger but clarified Thursday it was not deployed, only pulled out.

The bus driver wasn't hurt but the Amalgamated Transit Union said violence on city buses has become all too common.

"In this case we're concerned, we're very concerned about the fact that the passengers were at risk, our operator was at risk,” said ATU Local 1505 president Aleem Chaudhary.

Winnipeg Transit said it only tracks verbal or physical assaults against drivers.

So far this year the number of those incidents sits at 38, compared with 50 incidents recorded last year, 48 in 2016 and 62 in 2015.

Winnipeg Transit said if passengers see something concerning they should tell the driver or a transit supervisor instead of physically intervening.

In Wednesday’s incident the man who intervened suffered minor injuries but didn’t require medical attention.

Police said no one else was hurt.