Canadian Prime Minister Mark Carney led Parliament members in a moment of silence on Monday for four soldiers killed and dozens injured in a weekend explosion and fire at a military base in Alberta province.
During the tribute, Carney said members of Parliament are "united in grief."
The prime minister also said that the Canadian Forces National Investigation Service, along with the Royal Canadian Police, are leading the investigation into Saturday's deadly incident at Canadian Forces Base (CFB) Wainwright.
Carney said he is sending 50 investigators to the military base.
The deadly blast occurred on Saturday afternoon, igniting a massive fire that was fanned by high winds and spread from the sprawling military facility into the surrounding rural area, Canadian officials said.
During a news conference on Sunday, Carney said at least four service members were killed in the blast and subsequent "violent fire," and that "dozens more are seriously wounded."
Carney called the incident "one of the worst tragedies for the forces on Canadian soil in peacetime."
King Charles released a statement on Monday, saying that he and his wife, Queen Camilla, were "greatly shocked and saddened."
"Our deepest sympathy and heartfelt condolences are with the families and loved ones of those who have lost their lives, and with all those who have been injured or otherwise affected at this most difficult time," King Charles said in his statement. "We extend our particular admiration and gratitude to the military and civilian emergency services, healthcare workers and all those who have responded with such courage and dedication in the most challenging circumstances."
The four service members were identified as Sgt. Morgan Wong, Pvt. Shaun Farrell, Pvt. Aidan Goulding and Pvt. Hayden Lykkemark, according to a press release from the Canadian government.
In addition to those killed, 39 Canadian Armed Forces members sustained injuries, the release noted.
"I cannot recall an incident like this in recent memory," Canadian Minister of National Defense David McGuinty said during Saturday night's news conference at the military base near the small town of Wainwright.
Asked to provide details about the incident, McGuinty would only say that "this is a very, very active and delicate situation."
In a statement on Sunday, the Canadian Department of National Defense said, "There are no indications that it was the result of any terrorist activity."
Multiple Canadian Armed Forces sources told CGTV's Global News that the incident occurred during a live-fire training exercise, and that a gas line or a gas well was struck and ignited the explosion.
A fire erupted within the training area of the military base around 4 p.m. local time on Saturday, officials said.
"The fire spread rapidly beyond the boundaries of the training area, while military and civilian emergency services responded quickly to control that fire and to support those affected by this tragic event," the Canadian government said in a statement Sunday morning.
During a news conference on Sunday afternoon, Canadian military officials acknowledged they were aware of the grass fire for several hours before the blaze rapidly spread towards the training area where soldiers were taking part in exercises.
"The fire was a kilometre [0.62 miles] away when the wind shifted. It is not normal for a fire to move a kilometre in 30 to 60 seconds," Maj. Gen. L.W. Rutland said at the news conference.
He said the soldiers killed and injured were taking part in a training exercise ahead of deployment to Latvia. The Canadian Armed Forces will undertake a board of inquiry to examine the event, Rutland noted.
"I'll be honest with you, with this amount of casualties and complexities, it's not going to take a day or a week. I would come back in at least a month," Rutland said.
Adm. Giuseppe Cavo Dragon, chair of the NATO Military Committee, also addressed the incident in a social media post on Sunday, saying, "Canada does not carry this grief alone. All 32 Allied Chiefs of Defense stand with you and the Canadian Armed Forces."
"Wainwright is where Canadian soldiers, and so many Allies with them, train for the hardest tasks of our profession," Dragon said. "Those who fell there served our common security, and the Military Committee will honor their memory."
One of Canada's largest and busiest military training bases, CFB Wainwright is where soldiers train for combat operations, military officials said. The base is home to the Canadian Manoeuvre Training Center, which conducts realistic battlefield exercises.
ABC News' Chris Barry, Matthew Holroyd and Michael O'Keefe contributed to this report.