Frustrated with the lack of details about alleged Canadian involvement in a deadly Algerian gas plant attack, Ottawa has called in Algeria’s ambassador to Canada to get more information.

The federal government has been trying to verify reports that two Canadians were among the terrorists who stormed the natural gas plant and took hundreds of people hostage.

Algerian Prime Minister Abdelmalek Sellal said Monday that the al Qaeda-linked militant group included two Canadians -- one of them a leader of the attack. He said one of those men was Shadad Muhammed Amin, who spoke “with clear English,” and his accomplice was named Abdallah.

But Canada’s Foreign Affairs Department is demanding to see the men’s identification papers to determine if they are authentic or fake.

Canadian diplomats in Algeria are also requesting to see the documents Algerian officials are using to identify the attackers as Canadian.

“We are always concerned where there are reports that Canadians are involved in terrorism activities overseas,” said Public Safety Minister Vic Toews. “None of that has been confirmed.”

At least 37 hostages and 29 militants were killed when the terrorists ambushed the gas plant in a remote part of the Algerian desert.

U.S. officials are also looking into the attack, “to try to gain a fuller understanding of what took place, of who they deem to be responsible for this,” said Victoria Nuland, spokesperson for the U.S. Department of State.

Some experts doubt that a Canadian could have played a key role in the hostage-taking, as Sellal said.

The man who claimed responsibility for the gas plant siege is Mokhtar Belmokhtar, whose terror network has been formed through family and marriage ties.

“So it would be very difficult to imagine the circumstances in which a Canadian who didn’t have some of the same ethnic and familial ties would be a leader in this operation,” said J. Peter Pham, director of the Michael S. Ansari Africa Center.

With a report from CTV’s Ottawa Bureau Chief Robert Fife and files from The Canadian Press