OTTAWA -- A tightly packed crowd has gathered in the nation's capital for the national Remembrance Day ceremonies, marking 100 years since the signing of the armistice that ended the First World War.

Defence Minister Harjit Sajjan is attending the ceremony on behalf of Prime Minister Justin Trudeau, who is in Paris today, attending Armistice Day ceremonies with dozens of other world leaders, marking the conclusion of the "war to end all wars."

Participants in Ottawa have gathered under sunny skies and below-zero temperatures at the National War Memorial to pause and reflect on the sacrifices of Canadian men and women who have given their lives in conflicts around the world.

Gov.-Gen. Julie Payette is also in attendance, having just returned from a trip to Belgium for commemorative events. She greeted military veterans and special guests in attendance with friendly respects before the ceremony kicked off with a children's choir leading the crowd in singing the national anthem.

At 11 a.m., a sombre silence was broken by the beginning of a 21-gun salute and the deep tolling of a bell marking the solemn occasion.

A flyover of five CF-18 Hornet aircraft from Cold Lake, Alta., also flew over the crowd at the National War Memorial in a "missing man" formation.

Trudeau's wife Sophie Gregoire Trudeau accompanied Sajjan at the ceremony, and was joined by Senator Peter Harder, chief of the defence staff Jonathan Vance, Liberal MP Karen McCrimmon representing Veterans Affairs Canada and Thomas D. Irvine, national president of Royal Canadian Legion.

The national silver cross mother this year is Anita Cenerini of Winnipeg, whose son, Thomas Welsh, died May 8, 2004, three months after returning from his mission in Afghanistan. He was the first Canadian soldier to die by suicide after serving in the war in Afghanistan.

Earlier today, crowds of people filled the square at Halifax's Grand Parade to mark the occasion.

The sombre crowd stood in near-silence as it reflected on the battles that ended a century ago, and those that have come since.

The Halifax gathering is one of many being held across the country to mark the toll that war has taken on Canada's military personnel and their families over the last 100 years.

In Montreal, members of Canada's armed forces marched in to the sound of a beating drum.

Later today, Dominion carillonneur Andrea McCrady will play the bells in Parliament Hill at sunset as part of an initiative organized by the Royal Canadian Legion.

Bells will ring out as night falls in one place after another across the country, including at city halls and places of worship, on military bases and ships, and at ceremonies to honour veterans who served during the First World War.

McCrady will play "The Last Post" on the Peace Tower carillon, followed by striking the largest bell 100 times, at five-second intervals, which represents the moment in 1918 when bells across Europe tolled as the war came to an end.