OTTAWA -- Canadian fighter jets and other coalition aircraft have effectively flattened a warehouse in northern Iraq as part of a major nighttime operation against the Islamic State of Iraq and the Levant.

The attack took place near Mosul, the embattled country's second-largest city and was announced Tuesday in a news release from Defence Minister Rob Nicholson's office.

Four CF-18s dropped a total of eight precision bombs on the building, which was being used to train enemy fighters and to build roadside bombs and booby traps for use against Iraqi forces, the news release said.

All coalition aircraft returned safely without incident.

Later in the House of Commons, Nicholson confirmed the strike, but released no other details.

"All eight bombs hit their target and they did so simultaneously," he said. "This is a testament to the skill and professionalism of our armed forces. As always, Canada is doing its part to fight ISIL terrorism."

The attack was carried out in the overnight hours Monday to limit so-called collateral damage, said defence officials who spoke on condition of anonymity.

It is Canada's third bombing mission since CF-18 fighter jets began combat operations out of undisclosed bases in Kuwait at the end of October.

The officials, who were not authorized to release details publicly, insisted there were no civilian casualties, but would not speculate about whether any enemy fighters were killed.

The military was reluctant to admit last week that its second strike of the air campaign -- on a towed artillery piece -- had killed ISIL extremists. The commander of the country's Iraq task force would only say that it was "likely" that there were enemy casualties.

During the Afghan war, senior military commanders refused to discuss Taliban casualties, saying their measure of success did not involve body counts.

The fighter jets have flown a total of 52 sorties in the current campaign, National Defence said Tuesday.

The Canadian military also has two CP-140 Aurora surveillance planes and a C-150 refueller in the region. The Auroras have flown 15 missions to seek out ISIL targets,

Mosul is considered an Islamic State stronghold. Last week, U.S. commanders said in the coming months the city would be the focus of a major offensive designed to root out extremists.

Local media reports in Erbil, where Canadian and U.S. special forces are acting as advisers, say the operation to liberate Mosul is expected to begin early in the new year and could involve as many as 80,000 Iraqi troops.

Prior to the government's acknowledgment of the latest air strike, the assistant deputy minister of finance at National Defence appeared before the Senate finance committee.

Kevin Lindsey was questioned by a Conservative senator about the cost of the anti-ISIL campaign.

Lindsey did not reveal the estimated price tag, but said the department has not yet had to ask for additional funding.

The government has been criticized for not spelling out how much it thinks the bombing campaign and the simultaneous special forces training mission will cost.

"Obviously, we are just beginning our engagement," Lindsey said. "We don't know if we will need more money as we go along."

There will be another opportunity later in the fiscal year for the department to receive a top up and Lindsey said "to the extent additional funding is required, we will seek it at that time."