Chilling last photos of Canada's fallen soldier emerge

Chilling last photos have emerged of the slain ceremonial guard shot dead at Canada's National War Memorial this morning.

Nathan Cirillo, 24, was today identified as the sole casualty of the Ottawa shooting attack, which left at least three others in hospital with minor injuries.

Moments after the shots rang out, social media erupted with video and images of the fallen guard crumpled against the Tomb of the Unknown Solider as bystanders attempted to perform CPR.

But soon two very different photos emerged of Cirillo standing tall and on guard – one reportedly taken just minutes before his death.

In one picture posted to Twitter, Cirillo is shown in full dress uniform standing alongside a comrade at the memorial.

"OK, so we were on a tour at that war monument in Ottawa a few minutes ago, a few seconds later there was a shooting," a Twitter user known only as Evan captioned the photo.

In another more intimate snap, Cirillo poses smiling with a young woman at the same location.

"On Sunday, we asked a very handsome guard for a picture with my friend visiting from Cali - RIP Nathan Cirillo," Megan Underwood wrote.

Cirillo's auntie told The Globe and Mail her nephew was a member of the Argyll and Sutherland Highlanders, a Reserve regiment based in Hamilton.

She said he was training to join the Canada Border Services Agency.

David Cirillo, who identified himself as the soldier's cousin, took to Facebook earlier to express his anger.

"To the gunman that shot my cousin pint blank in front of the Parliament Hill this morning for no reason, you will get what's coming to you," the post read.