A hospital run by a Canadian non-profit organization that operates in Syria has been bombed, marking the second attack on a civilian hospital in the war-torn city of Aleppo in the last three days.

UOSSM-Canada, the Canadian chapter of the Union of Medical Care and Relief Organizations said on its website Friday, that the Al Marjeh Primary Health Care Centre in Aleppo was "completely destroyed" in the attack.

No one was killed in the bombing because it happened on a local holiday.

"We do have some minor injuries, but thank God nobody died in this facility," Anas Al Kassem, a Canadian-Syrian surgeon from Oakville who heads the UOSSM-Canada, told CTV News Channel on Friday.

"Physicians were not in the building at the time the attack happened, so we did not lose any patients or physicians when this happened," he said.

The organization said Canada has sent millions of dollars' worth of medical supplies to this facility since it opened in 2014.

The health centre serves internally displaced people in Syria, and reports that 82 per cent of its patients are women and children. The facility offered non-emergency services such as X-rays, treatment for diabetes, dental care and a specialized pediatric unit.

No Canadian doctors have worked at the hospital in the past year due to ongoing attacks in the region, Al Kassem said.

UN Secretary General Ban Ki-moon condemned the bombing, calling attacks such as this "inexcusable violations of humanitarian law."

In a statement, Al Kassem called the targeting of hospitals a "war crime."

"We strongly condemn these actions and ask the international community to act and protect hospitals and aid workers," he said. "It's time the international community took action to stop these crimes against humanity."

Al Kassem says the hospital will be forced to relocate to a new area after the bombing. He says the facility has repeatedly moved since airstrikes picked up last September.

UOSSM-Canada blamed Russian and the Syrian forces for the airstrikes.

Rebel forces in Aleppo have been targeted in a series of recent aerial attacks that have devastated the war-torn city and killed more than 200 people in the last eight days. A mosque, several medical facilities, bakeries and a water station have all been caught up in the violence.

The fighting signals the collapse of a two-month ceasefire between the U.S. and Russia, and raises new fears of ramped-up attacks on Aleppo by the Syrian government.

Security expert: 'Was this an accident?'

Questions linger as to why Russia, if responsible, would target an empty hospital funded by a Canadian non-profit. A leading national security expert called the attack "shocking on so many levels."

"The real question is, really, was this an accident," said Anthony Seaboyer, a political scientist with the Canadian Royal Military College.

"If it was deliberate, what can we still rely on with our dealings with Russia? What is still sacrosanct and will not be crossed? What lines are still existing? I think that’s the question we’re looking at here at this point."

Russia possess highly sophisticated targeting technology, which belies claims of accidental airstrikes, Seaboyer said.

"It’s hard to believe that you’d see so many accidents within such a short time. It’s much more logical that this would be, to some extent, a deliberate action," he said.

Canada’s next step should involve talks with Russia to clarify exactly what happened, Seaboyer said.

"I think we have to engage in talking to them, first of all, finding out what really was happening here. We have to re-establish a clear rapport of what line will not be crossed," he said.

With files from The Associated Press