Shots fired in the Canadian capital Wednesday killed soldier Nathan Cirillo, 24. Striking photos of the event were captured after the unidentified shooter opened fire at the National War Memorial in Ottawa. 

House of Commons Sergeant-at-Arms Kevin Vickers, 58, was called a hero after he stopped the shooter, CBC News reported. Two sources said he shot the assailant; the circumstances have not been confirmed. 

Ottawa police A Royal Canadian Mounted Police officer stands guard on Metcalfe Street following shootings in downtown Ottawa October 22, 2014. A Canadian soldier was shot at the National War Memorial in downtown Ottawa and a gunman was shot and killed in a nearby parliament building, media and witnesses reported. Photo: REUTERS/Blair Gable

More than one person was reportedly involved in the shooting, which means an additional gunman could be on the loose. "We have to apprehend and arrest the people that are involved in this morning's incident," Ottawa Police Constable Chuck Benoit told CNN, "and at this time we don't have these people."

Canada Nathan Cirillo was identified as the soldier who was killed in the Ottawa shooting Wednesday. Photo: Reuters

Police said the hunt to find more suspects is “ongoing” and “fluid.” There is no confirmation that Wednesday’s attacks were led by Islamic State (ISIS) militants, the BBC reported.

One gunman was shot after police stormed the National War Memorial, the news site wrote. Three people were taken to the hospital. Cirillo died, and two are in stable condition at Ottawa Hospital.

RTR4B6LG Ottawa Police sent a letter to local religious leaders to discuss the shooting at Parliament and how they could help. Police officers patrol the scene near the Canada War Memorial following a shooting incident in Ottawa October 22, 2014. A Canadian soldier was shot at the Canadian War Memorial and a shooter was seen running towards the nearby parliament buildings, where more shots were fired, according to media and eyewitness reports. Photo: Reuters/Chris Wattie

President Barack Obama said Wednesday the shootings in Ottawa highlight the "degree to which we have to remain vigilant," CNN reported. He told reporters: "We don't yet have all the information about what motivated the shooting. We don't yet have all the information about whether this was part of a broader network, or plan, or whether this was an individual, or series of individuals, who decided to take these actions."

Canada Shots fired at the Canadian capital Wednesday killed soldier Nathan Cirillo, 24. Photo: Reuters

Cirillo was guarding the National War Memorial when he died, Ottawa police announced at a press conference. "Remember how one person's life has been take -- from his family, from his friends, from the future that was supposed to be his," said Ottawa Mayor Jim Watson, according to the CBC News.

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