Meanwhile, sources have confirmed to CTV News that a gunman has been killed. Ottawa police will not confirm if the three shootings are the work of a lone gunman.

Earlier Wednesday, a solider was shot at the War Memorial and a security guard was wounded at Parliament Hill, which remains under lockdown.

Video captured inside Parliament showed officers filing down the empty halls of the Hall of Honour as at least a dozen shots can be heard ringing out in the background.

Jason MacDonald, director of communications for Prime Minister Stephen Harper, tweeted that Harper is safe and has left the area.

The RCMP is advising people to stay away from the area, and people in downtown Ottawa to stay away from windows and off of roofs.

Several MPs also took to Twitter to say that they were safe. Several described what they had heard, and many said they were in hiding.

MP Tony Clement tweeted that at least 30 shots were heard from inside the building, close to where the Conservatives and the Liberals hold their weekly caucus meetings.

Police confirmed that they received a call about shots being fired just before 10 a.m. on Wednesday morning. They said a man believed to be a member of the Canadian Forces was shot at the National War Memorial.

Witnesses at the memorial told CTV News' Katie Simpson that they saw a man with long hair carrying a rifle and heard four shots fired.

One witness told her that he saw the man with the rifle then run towards Parliament Hill.

The shooting comes two days after a man attacked two Canadian soldiers in St-Jean-sur-Richelieu, Que. One of those soldiers died from his injuries. The suspect was shot and killed by police.

On Tuesday, Canada raised the domestic terror threat level from low to medium.

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