Postpublished at 19:51 BST 22 October 2014
Prime Minister Stephen Harper, making his first statement after the shooting, has described it as "a despicable attack". He says it is important for the government and parliament to continue to function.
There have been two shooting incidents in Ottawa - at the National War Memorial and inside parliament
A soldier guarding the war memorial was shot and later died of his injuries
A gunman has been killed in the parliament building, it is not clear if other gunmen are at large
Several buildings are on lockdown and residents have been told to stay away from windows and roofs
PM Stephen Harper says "Canada will never be intimidated" and will "redouble our efforts" in fighting terrorist groups
Sherie Ryder, Yaroslav Lukov, Mike Hills, David Walker, Victoria Park and Bernadette McCague
Prime Minister Stephen Harper, making his first statement after the shooting, has described it as "a despicable attack". He says it is important for the government and parliament to continue to function.
The police press conference gave us very few new details. Still not clear if only one gunman involved.
This image shows the Conservative Party caucus room shortly after the shooting began, with chairs piled against the doors to act as a barricade
Canadian police say the attack "caught us by surprise". A spokesman said: "If we had known that this was coming we would have been able to disrupt it."
Police are refusing to say whether there was more than one gunman involved in Wednesday's shootings.
Ottawa Mayor Jim Watson says it is a "sad and tragic day for this city and the country".
An Ottawa police chief describes the situation as "dynamic and unfolding" and says "we are committed to providing answers as soon as possible".
Ottawa police looking for witnesses to come forward, press conference told.
Canadian police have said at a press conference that the situation is "fluid and ongoing".
Police say there is an "ongoing joint police operation and there is no one in custody at this time". It adds that Ottawa residents are "asked to stay away from the downtown area while the investigation continues."
UK Prime Minister David Cameron has tweeted about today's events in Ottawa, saying, external: I'm appalled by today's attack in Ottawa. I offer my full support to @pmharper and the Canadian people as they deal with this incident.
In a statement, external, the RCMP says reports of an incident at the Rideau Centre were incorrect, but confirms the two other shooting incidents at the National War Memorial and in the parliament building.
The Royal Canadian Mounted Police (RCMP) have confirmed that the soldier shot at the National War Memorial has died. One of the suspects has also been confirmed dead.
We are expecting police to hold a news conference in the next few minutes.
Mark Day, 1310News, Ottawa tweets, external: #Toronto police Chief Bill Blair will speak @ 2:15pm on precautions being taken by Toronto police after shootings in #Ottawa
Police have set up checkpoints on several roads out of Ottawa. There were earlier reports that a gunman may have fled the scene on a motorbike but we've had no confirmation of that. Amer Adas, an Ottawa resident, captured his journey through one such checkpoint in a short video, external.
Jessie Inman, CEO Confederation Centre of the Arts tweets, external: In Ottawa @ Westin Hotel watching events unfold #OttawaShooting So sad solider guarding our war memorial died @CBCPEI @PEIGuardian @CBCNews
Robert Gagnon emails: Still in lock down in government defence building two blocks east of Rideau Centre shooting location. No news in the last two hours. Eerily quiet. Not allowed in or out. Streets are empty.
Harry Adams
tweets:, external @BBC_HaveYourSay Terrible tragedy in progress in #Ottawa #Canada. Much respect to the people involved. Stay safe
According to a cabinet minister, the shooting in the parliament building happened while Prime Minister Harper was addressing the cabinet. The unnamed minister told Reuters news agency the gunshots were "right outside out caucus door".
Officials confirmed Mr Harper made it safely out of the building shortly after the incident.