Canadian Special Operations Forces assisted Kurdish soldiers in a prolonged battle against ISIS militants in northern Iraq, returning fire from the ground as two CF-18s dropped bombs.

Canadian Armed Forces Maj.-Gen. Charles Lamarre told reporters in Ottawa Thursday about what he called “the largest event that the Canadian Armed Forces training up north have been involved in.”

The 17-hour offensive east of Mosul began around 4 p.m. local time on Wednesday, and involved suicide bombs, ground troops and artillery.

When the battle began, Canadians soldiers were six kilometres from the front lines, sources told CTV News. But Lamarre said some were “close enough and able to respond with fire” during the major offensive.

Lamarre was asked whether this meant Canadian Forces were involved in combat.

“Our guys are always prepared because it’s a dangerous environment and they need to be able to defend, not only themselves, but the forces with which they are training and providing assistance,” Lamarre said. “This was an engagement where they had to be able to return fire.”

Lamarre would not say how many of the 69 Special Operations Forces were involved or what type of weapons were used.

There were no Canadian casualties, but Kurdish security forces “sustained a number of losses,” according to Lamarre.

He called the event “significant” because of the “size of the (ISIS) contingents” and the “success that the KSF are having in being able to contain those types of attacks … and of course the role our guys are playing in helping to make sure they’re trained up and prepared.”

Lamarre said the two CF-18s that assisted “were already up in the air” at the time of the attack.

Asked whether the Liberal government should rethink their plans to pull Canada’s six CF-18 fighter jets from the fight, Lamarre said that’s for the government to decide.

“The coalition was able to bring forward strike fighter aircraft that were helpful in re-establishing the line,” he added.