OTTAWA -- None of the seven Canadian soldiers treated at a military hospital in Iraq over the last few weeks was a combat casualty, says National Defence.

The department earlier refused to discuss how the soldiers were injured, but now acknowledges they were being overly cautious.

Military spokeswoman Maj. Kendrah Allison said in an email the service members seen at a Canadian Forces-run hospital near the city of Erbil since the end of November were treated for various medical problems.

She says three were treated for illnesses such as gastrointestinal issues or heatstroke and four were treated for burns, breaks and other "non-battlefield injuries."

The hospital was set up to support the battle for the city of Mosul, which is currently held by the Islamic State of Iraq and the Levant.

Opposition critics had questioned whether the Liberal government was trying to hide the fact Canadian soldiers had been wounded in combat.

Daniel Le Bouthillier, head of media relations for the department, said casualty numbers were released periodically during the Afghan war, when there were far greater numbers of Canadians deployed.

Since the Iraq mission is much smaller, "there were concerns members could be identified by process of elimination" if casualty details were released, Le Bouthillier said in an email.

That reflected "an overabundance of caution," he wrote.

"We are looking at options that will allow us to effectively respond to similar requests for information in the future, while still protecting CAF personnel taking part in this operation."

Canada has about 200 soldiers operating alongside Kurdish forces in northern Iraq, where they have been providing training and advice in the fight against ISIL.

They have also at times fired on ISIL forces, though military commanders insist the troops are not engaged directly in combat and fire only to protect themselves, friendly forces or civilians.

The Canadian-run military hospital has treated 120 patients since the end of November, including the seven Canadians and three captured ISIL fighters.