Harper spent as much as 15 minutes in the tiny space off a meeting room where he and his Conservative caucus were meeting, AFP report further added.
Earlier on Wednesday, Harper condemned three confirmed incidents of shooting inside the country's Parliament buildings, War Memorial and a shopping mall in the country's capital Ottawa.
A Canadian soldier shot and wounded by an unidentified gunman at the National War Memorial in Ottawa. Canadian Police also said that there was an involvement of numerous gunmen in the shooting incidents.
In a speech to the nation, Harper said Canada faced a violent attack on its soil for the second time in a week, adding that the country would learn more about the terrorist and their accomplices.
He said: "...this week's events are a grim reminder that Canada is not immune to the types of terrorist attacks we have seen elsewhere around the world."
Harper also prayed for the family and friends of Cpl Nathan Cirillo of the Argyll and Sunderland Highlanders, who was fatally shot and hoped for a speedy recovery of others injured in the attacks.
"We are also reminded that attacks on our security personnel and on our institutions of governance are by their very nature attacks on our country, on our values, on our society, on us Canadians as a free and democratic people who embrace human dignity for all," the Canadian prime minister said.
Harper also said the attacks will only make Canada stronger in its resolve and it will work with its allies around the world and fight terrorist organisations.