Despite a significant decline in bus-related violence, an overnight stabbing on board an ETS vehicle is leading to renewed calls for more safety measures.

EPS sealed a perimeter around the low-level bridge at 12:20 a.m. Sunday after a fight broke out among three people, all of whom are known to police. One man suffered non-life-threatening knife wounds and another broke his orbital bone.

Officers say the situation was quickly contained thanks to the coordinated efforts of transit officials and police. All three suspects, who range in age from 19 to 21, were arrested shortly after the incident and charged with aggravated assault.

"We were able to quickly utilize the services of the K-9 unit and air support to lock down the area," said Acting Insp. Tom Farquhar. "You can see by the response the Edmonton Police and in particular the ETS service takes this very serious. It's a coordinated effort here tonight to make sure the transit buses are a safe place to be."

Despite that effort, and a reported 23 per cent decline in violence on city buses, the head of the ETS union argues more resources need to be dedicated to the cause.

"I get calls everyday from operators who say, ‘you know what, I don't feel safe anymore. I want to quit,'" said Stu Litwinowich. "[Police are] not going to be out there when there is fare evasion, or someone spitting on an operator. We need transit peace officers."

Litwinowich qualifies that argument by saying the city and officers are doing a good job addressing the issue, adding ten peace officers to the transit system after a brutal attack on bus driver Tom Bragg in December 2009. Still, his union had asked for 21.

Officials say they will discuss ways of better coordinating efforts between peace officers and police officers on Monday.

"When people choose to use public facilities they should feel safe and comfortable with that environment, so we will continue to keep this a high priority," said city manager Simon Farbrother.

With Files from Sean Amato