The soldiers' deaths have prompted grief and outrage
There are signs of growing resentment and even anger in Canada in response to the "friendly fire" incident in Afghanistan, which killed four Canadian soldiers and injured eight others.
A US F-16 dropped a 227-kilogram bomb on the men on Wednesday while they were taking part in a live-fire training exercise.
Flags have been flying at half mast throughout Canada as relatives and friends of the soldiers have been speaking about their loss.
Bouquets of flowers have been placed outside their base in Edmonton, Alberta.
Mixed responses
Thousands of Canadians have been sending their thoughts to media websites, and amid the grief expressed about the tragic accident, there are also many messages from people who are angry that the soldiers were killed by their allies.
Some have called for the Canadian forces to be pulled out of Afghanistan.
Others are upset about what they feel is the inadequate response of US President George W Bush to the incident.
He made several public appearances in the hours after the news broke, but only made a brief statement after he was asked a question by a journalist.
On Friday, two days after the incident, he expressed his sorrow.
"It was a terrible accident. I wish we could bring them back. We can't. We'll find out what took place."
He also spoke of his gratitude "for the sacrifices the Canadians are making in the war against terror".
The opposition leader in Parliament, John Reynolds, said he was disappointed with Mr Bush's response.
"I would have hoped that the president of the United States would have said something to these families. I'm sure he feels sorry about it, just like he does when his own soldiers were killed," he said.
An email to the Canadian Broadcasting Corporation (CBC) website put it more strongly:
"I am appalled at President Bush's casual dismissal of the "friendly fire" incident in Afghanistan," Mark Ojah, a Canadian from Winnipeg, wrote from Texas.
"It appears that the president would not even have publicly acknowledged the tragedy had it not been for the prodding of a Canadian journalist who caught Bush on camera as he attempted to scurry away."
Accidents happen
But others recognised that accidents happen during war, and that US soldiers have also been killed in friendly-fire incidents.
Americans have also been sending messages expressing sympathy and solidarity with Canadians.
Meanwhile, the relatives of those killed have been speaking about their loss.
Marlet Leger, the wife of Sergeant Marc Leger, who was one of the four killed in the incident, said all the soldiers were heroes.
She said her husband felt that he had to be part of this conflict.
"He said, I can't let what happened continue, it's my job and this is what I'm meant to do."
'Non-war'
But some Canadians see the accident as a reason to withdraw.
"Get them out now.... They're fighting a non-war, and non-wars can never be won," Tom Atherton wrote to the Globe and Mail website.
Britton Cole of Kingston, Ontario wrote to the CBC website: "The level of incompetence in the mighty US armed forces is inexcusable."
The leader of the left-wing New Democratic Party Alexa McDonough echoed those views when she said the troops should be pulled out because the terms of engagement weren't defined clearly enough.
Others tried to put the accident in a wider context.
Jim Dunk of Campbellford, Ontario, wrote to CBC: "We should not be entirely surprised by the tragic deaths of Canadians in Afghanistan. There are always risks associated with actions of the kind our troops are exposed to in that country."
But he also criticised the "cowboy" mentality of Americans who shoot first, ask questions later.