The victims were identified as Martin Glazer of Gatineau and Peter McSheffrey of Ottawa. Both worked at the Gatineau, Que.-based consulting firm Samson and Associates.
The McSheffrey family said it's grieving the loss of "a beloved husband, father, brother and son."
"What makes this particularly difficult for the family is that Peter was a victim of senseless violence against innocent people," the family said in a statement posted on the firm's website.
"Peter loved to travel and was doing meaningful work."
Glazer's family said that Glazer also felt he was making an important contribution.
"He took pride in the work that he did, contributing to Canada's efforts to bring about peace and security in Afghanistan by helping to ensure that development assistance money went to those it was intended to assist," the family said.
At least 21 people were killed in Friday's attack, one of the deadliest against foreign civilians since the war began nearly 13 years ago.
A suicide bomber blew himself up outside La Taverna du Liban, a restaurant popular with foreigners and affluent Afghans, while two gunmen snuck in through the back door and opened fire.
Pierre Samson, the president of Samson and Associates, said his two employees were having dinner at the restaurant when the bomb went off.
They had been in Kabul less than a week doing an audit for the Canadian International Development Agency, Samson said.
"This is the first time that we've ever had such a thing," he said in a phone interview, explaining that his firm has done work in Afghanistan for some time.
"As auditors we're not on the front (lines) so we don't usually go where it is very dangerous, but in a case like this the attack was directly in town, so it was not in a danger area. But unfortunately we were there at a bad time."
Samson said his firm received news of their deaths on Friday evening from the Canadian embassy in Kabul.
Kabul police chief Gen. Mohammad Zahir Zahir said Saturday that the victims included 13 foreigners and eight Afghans, and that most were civilians.
Three United Nations personnel and the International Monetary Fund's representative in Afghanistan were also among those killed, officials said.
The Taliban claimed responsibility.
The deaths come as Canada is nearing the end of a military training mission in the country.
The restaurant is located close to Canada's embassy in Kabul and is a popular spot for expats in the capital.
In addition to the Canadians, those killed included two U.S. citizens working for the American University of Afghanistan, a victim identified by the United Nations as a Somali-American, two Britons, two Lebanese, a Danish police officer, a Russian, a Malaysian and a Pakistani.
Foreign Affairs Minister John Baird condemned what he called a "cowardly terrorist attack."
"On behalf of all Canadians, we extend our sincerest condolences to the families and friends of those who were killed and injured in this horrible and senseless act of terror," he said in an email statement.
The attack was also widely denounced by the international community, including the United Nations Assistance Mission in Afghanistan.
"I strongly condemn the targeting of civilians in any form, and, in particular, the continued use of suicide bombers," said Jan Kubis, the secretary-general’s special representative for Afghanistan.
"This violence is unacceptable and must stop immediately."
- by Benjamin Shingler in Montreal with files from The Associated Press
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