The Canadian government says it has confirmed that two of its citizens died in Israel over the weekend, and a third is presumed to be dead.

Two of the confirmed casualties were named in local media as Ben Mizrachi, a 22-year-old from Vancouver, and Alexandre Look, a 33-year-old from Montreal.

Both were at the Supernova music festival in southern Israel on the morning of 8 October, when Hamas militants attacked the festival site.

On Wednesday, a third victim was named by the Jewish Federation of Ottawa. Adi Vital-Kaploun, 33, was reportedly killed in her home at Kibbutz Holit, about two kilometres from the Gaza Strip.

"Our family lost a mother, a wife, a sister, a daughter, a granddaughter, a niece, a cousin," said Andrea Freedman, the CEO of the Jewish Federation of Ottawa, at a news conference.

"Her children are miraculously safe," she added.

Three other Canadians remain missing, according to Global Affairs Canada, and their families fear they are being held hostage in Gaza.