CNN) -- A Canadian soldier was shot and killed as he and another soldier stood guard at Canada's Parliament war memorial Wednesday. Details are emerging as authorities try to secure the government building in Ottawa.The violence is not confined to Parliament. Police say that there could be multiple shooters and that there are three shooting incidents in the capital.Ottawa police, whose buildings were also locked down, provided details on Twitter about multiple shootings: "Incidents occurred at National War Memorial, near the Rideau Centre and Parliament Hill."The Canadian government told the United States that one shooter is dead in Ottawa, a senior U.S. official told CNN. So far, there is "no indication the shooter has ties to violent Islamic extremism," but it is still extremely early in the investigation, the source said.

The FBI is helping Canadian authorities as they respond, a U.S. law enforcement official told CNN, adding that a connection to terrorism hasn't been ruled out.In response to the ongoing situation, the North American Aerospace Defense Command, or NORAD, has increased its alert posture, CNN has learned. That means that it has increased the number of planes on a higher alert status ready to respond if needed. NORAD and Canadian authorities are in contact, an official told CNN.At least one shooter is dead, Parliament member Bob Zimmer tweeted earlier.Parliament remains on lockdown.No one was hurt in a shooting near Ottawa's Rideau Centre, Marc Soucy of the Ottawa Police Service told CNN. It was one of three shootings, he said. The other two were at the National War Memorial and Parliament Hill.Shots rang out at Parliament around 10 a.m. ET as members, including Prime Minister Stephen Harper, prepared for caucus. Some members tweeted that they heard many shots.Prime Minister secureMP Tony Clement tweeted that he heard "at least 30 shots" and apparently was able to take cover with colleagues.He tweeted that Harper was secure.Harper was evacuated from the building and is safe, tweeted his press secretary, Carl Vallee."@PMHarper is safe and he has left parliament hill," Vallee tweeted in French.Hours after the Parliament attack, Harper spoke by phone with U.S. President Barack Obama.In the hurried time shortly after the shooting, Peter Henderson, a journalist, said there were soldiers doing drills when shots were fired. He said he knew the person shot was a soldier because of the ceremonial uniform the soldier was wearing."I heard rapid fire -- gunshots going very loud -- and I figure maybe 20-plus shots within 10 seconds," Canadian Deputy House Leader Kevin Lamoureux told CNN.He was inside Parliament, caucusing with fellow lawmakers, when a security officer told them to leave the building. Lamoureux said. "I honestly thought it was a fire alarm situation," he said.Then he heard gunfire. He was on the ground floor, one level below the gunshots, and was among those who evacuated outside and were moved to safety in another building nearby.There was panic as people rushed out a door, he said. Lamoureux said he heard no screaming or other sounds before the shots rang out.

Every where.God save us oooo