Two Canadians involved in a deadly terrorist attack and hostage-taking at an isolated Algerian natural gas plant were from London, Ont., federal officials confirm.

The men have been identified as 22-year-old Xristos Katsiroubas and 24-year-old Ali Medlej, CTV News Ottawa bureau chief Robert Fife reported Tuesday.

Both men died in January’s four-day siege, which ended when Algeria’s military stormed the complex, leaving at least 38 hostages and 29 al-Qaida-linked militants dead

Katsiroubas and Medlej were described as high school friends who grew up in London, Fife told CP24.

Their families have been informed of their involvement in the attack and their deaths, as police and the Canadian Security Intelligence Service (CSIS) look into whether any of their friends were involved in the plot, sources told CTV News.

According to reports, two men from the London, Ont. area travelled to Algeria with Katsiroubas and Medlej, but it is not known if they were involved in the attack or if they are alive.

Katsiroubas was Greek Orthodox but he converted to Islam around the age of 17 or 18, and he somehow became radicalized, Fife said.

CSIS and police are investigating how the men were recruited and how they became involved in the deadly attack.

CSIS reportedly began asking questions about Katsiroubas and Medlej after family members became concerned and contacted authorities in 2007.

At a news conference Tuesday, members of the London Muslim Association condemned the attacks and the London men’s involvement in the plot.

A spokesman said the association and local mosque do not know the men or their families.

Because the men were from London, the association is worried there will be a backlash or discrimination against local Muslims, or racial stereotyping of Muslims and Islam.

The association said people are wrong to draw a connection between the terror attack and Islam.

Foreign Affairs Minister John Baird attempted to avoid questions about the report Tuesday, but he said homegrown terrorism is not unique to Canada and it should be of grave concern to Canadians.

Baird spoke to reporters in Abu Dhabi during an overseas trip to the Middle East.

After January’s attack, Algerian Prime Minister Abdelmalek Sellal claimed two Canadians were among the band of militants who ambushed the gas plant and took workers hostage.

Canada’s Foreign Affairs Department initially couldn’t confirm Sellal’s claim and it later sent RCMP officers to Algeria to investigate.

The RCMP eventually identified the bodies of the two Canadians.

Hostages who escaped recalled hearing at least one of the militants speaking English with a North American accent.

With files from CTV News Ottawa bureau chief Robert Fife and The Canadian Press.

@ChrisKitching is on Twitter. For instant breaking news, follow @CP24 on Twitter.