Alan Merizier, Waiter, Canadian Parliament
A waiter working in the parliament building, Alain Merizier, witnessed the attack on Wednesday morning.
"I was going to work at the parliamentary dining room," he said, "when I heard a police car siren and realised something was happening to the parliament."
Mr Merizier described seeing a dark car stop outside parliament's centre block and a driver with "a long gun" get out and run inside the entrance of the building, hotly pursued by a parliamentary officer.
Mr Merizier said that the attacker was of "Arabic appearance" and had "long dark hair and a beard".
"After I heard one shot, I took a picture of his car," he said.
"I was astonished more than frightened. You don't have time to be afraid."
Mr Merizier said his colleagues in the parliamentary restaurant were later "locked down" in the building.
John McKay, Canadian MP
MP, John McKay, was in the parliament building at the time of the attack.
"There was a pop, pop, pop sound so the guards ushered us to the back of the building" he said.
"How the gunman was able to walk down the hall of honour inside parliament with a rifle will become an area of investigation."
"It was bizarre, not something that we have ever experienced before," the Canadian MP added.
Percy Downe, Canadian Senator
Senator Percy Downe spoke to the BBC from his office on nearby Parliament Hill.
He said he knew there was an "elevated level of threat" when he saw police officers arrive at the the scene and "put on their bullet proof vests and get their machine guns".
David McGuinty, Member of Canadian Parliament
Canadian MP David McGuinty told the BBC there was a "palpable sense of fear" in Ottawa as the lockdown affected parliament, the nearby University of Ottawa, police buildings and the US embassy.
"It's extremely unusual for such an atmosphere to exist in the city," he said.
Mr McGuinty said security at the Canadian parliament had been weak: "In [the] Westminster [parliament in London] for example, security screening is done outside the building, but that's not the case here in Canada."
Eyewitnesses of the attack in Ottawa gave these accounts of Wednesday's extraordinary events to the BBC.