One person has been injured in the incident.

Ottawa Police tweeted: "Shots fired at War Memorial at 9:52am today; one person injured. More details to come when avaialble #ottnews."

"All Ottawa Police stations are closed to public due to shooting at War Memorial. No public services available until further notice #ottnews," it said.

Several MPs also tweeted that they were safe following the shootout.

 MP Tony Clement tweeted: "Shots fired during caucus meeting. at least 30 shots. MPs piled out. I'm safe with 2 colleagues but we're still at risk...I'm with colleages Mark Strahl and Kyle Seeback. PM was in Caucus but now secure. Assuming it's not safe to venture out yet."

MP Michelle Rempel posted on her Twitter homepage: "Mom im okay Im in hiding."

She again said: "is it clear people? shots were outside caucus room."

According to reports, the gunman rushed towards the Parliament Hill.