The first strikes of Canada's air war over Iraq appear to have been aimed at construction equipment belonging to the Islamic State in Iraq and Syria.

Although the military has been silent about what targets were bombed by two CF-18s during Canada's first air raids of the war, the U.S. command overseeing operations in the Gulf region released a list of the weekend bombing missions.

Government sources told CBC News the target that was hit was deemed to be of strategic importance.

The only official Canadian acknowledgement came from Defence Minister Rob Nicholson, who said Sunday's attacks took place in the area of Fallujah, a militant stronghold about 71 kilometres west of Baghdad.

Nicholson wouldn't release details, but said more information would be forthcoming at an Ottawa briefing on Tuesday — 48 hours after the mission.

However, U.S. Central Command, based in Tampa, Fla., said four strikes hit a large ISIS unit in the vicinity where Canadian planes reportedly dropped their laser-guided bombs.

The attack apparently destroyed five ISIS bulldozers and one ISIS dump truck used to build obstructions and berms.

It is unclear whether Canadians carried out all of the strikes in the vicinity of Fallujah or if aircraft from other coalition nations were involved.

No one at the Canadian task force headquarters was immediately available for comment Monday night.

No mention of Canadian involvement

The U.S. military says a total of nine airstrikes took place in Iraq on Sunday, using jets and drones. Interestingly, the news release from U.S. Central Command neglected to mention Canada's involvement in air operations.

The Iraqi government lost control of Fallujah in early January after local police were unable to hold back fighters from ISIS, also known as ISIL, in the aftermath of the withdrawal of army units from Anbar province.

An offensive to retake the key region, which was the scene of some of the heaviest fighting during the U.S. occupation, began in late September.

The battle, which has involved tanks and armoured vehicles, has ebbed and flowed throughout October. There were reports in local media last week that as many as 400 ISIS fighters had massed in the area, which has been repeatedly bombed by coalition aircraft.

The construction equipment might have been used for constructing defensive positions for militants.

A total of six CF-18 jet fighters, two CP-140 Aurora surveillance planes and one C-150 refuelling jet are operating out of airfields at an undisclosed location in Kuwait.

The warplanes receive their strike orders and targets from the U.S.-led coalition and join aircraft from a number of different countries, including the U.S., Britain, Australia and several Gulf states.

The Canadian contribution to the air campaign is mandated to last six months, but is likely to be extended.