Gunfire echoed through the Gothic halls of the Canadian parliament Wednesday as police shot dead a gunman suspected of killing a soldier guarding a nearby war memorial before storming the building.
Police said an investigation was continuing, but did not confirm earlier reports that more gunmen were involved. Heavily armed officers backed by armored vehicles sealed off the building.
There was no immediate word on the gunman's motivation, but the attack came a day after an alleged Islamist drove over and killed another soldier in what authorities branded a terrorist attack.
Authorities had raised the security threat level from low to medium after the car attack, which came as Canadian jets were to join the US-led air armada bombarding Islamist militants in Iraq.
Prime minister Stephen Harper warned that "facts are still being gathered" but nevertheless "condemned this despicable attack."
"One shooting victim succumbed to injuries. He was a member of the Canadian forces. Our thoughts and prayers are with his loved ones," the Ottawa Police and Royal Canadian Mounted Police said.
"One male suspect has also been confirmed as deceased," they said, in a joint statement, calling on witnesses to come forward and for residents to stay clear of Ottawa's downtown area.
Later, a police spokesman said two people received "minor injuries" in the incident, but refused to say whether more gunmen could be at large or what might have triggered the attack.
"We're still investigating the active operation. We're in the process right now," he said.
Lawmakers, staff and reporters evacuated from the building spoke of intense gunfire in the historic building on Parliament Hill.
Video footage posted online by the Globe and Mail newspaper showed police ducking for cover as they advanced along a stone hallway, loud gunfire echoing among parliament's stone columns.
'Pop, pop, pop'
A member of parliament, Maurice Vellacott, told AFP that House of Commons security had told one of his aides that the suspect had been killed inside parliament.
"I literally had just taken off my jacket to go into caucus. I hear this 'pop, pop, pop,' possibly 10 shots, don't really know," Liberal Party member John McKay told reporters outside.
"Suddenly the security guards come rushing down the hallways and usher us all out to the back of the parliament buildings," he said, as lawmakers, staff and reporters scurried from the area.
Witnesses said the soldier was gunned down at point-blank range just before 10 am by a man carrying a rifle and dressed all in black, a scarf over his face. They said the gunman then ran off and entered Parliament, a few hundred yards away, where numerous shots soon rang out.
One witness, parliamentary aide Marc-Andre Viau, said he saw a man run into a caucus meeting at the parliament, chased by police armed with rifles who yelled "take cover."
That was followed by "10, 15, maybe 20 shots," possibly from an automatic weapon, he said. "I'm shaken," said Viau.
Police raced to seal off the parliament building and Harper's office, pushing reporters and bystanders back and blocking roads.
Harper -- who was attending a meeting with lawmakers in parliament at the time -- left the area of the shooting and was "safe," his spokesman Jason MacDonald said.
A Royal Canadian Mounted Police intervention team responds to a reported shooting at Parliament building in Ottawa on Wednesday. (AP Photo)
In Canada's southern neighbor the United States, President Barack Obama condemned the attack as "outrageous" after talking by telephone with Harper, the White House said. An official said US and Canadian air defenses were on alert.
The US embassy in Ottawa was placed on lockdown.
The incident came a day after 25-year-old Martin Couture-Rouleau ran over a soldier, killing him before being shot dead by police as he emerged from his wrecked car wielding a knife.
The government branded this a terrorist attack by a suspected Islamist, amid reports that Couture-Rouleau was a supporter of the so-called Islamic State, a jihadist group operating in Iraq and Syria.
If the driver's alleged jihadist sympathies are confirmed, it would be Canada's first-ever Islamist attack, although authorities have warned they are tracking 90 suspected extremists already in the country.
The government said the heightened threat level "means intelligence has indicated that an individual or group within Canada or abroad has the intent and capability to commit an act of terrorism."
After the incident, police told people in downtown Ottawa to stay away from windows and off roofs. The soldier who was reported to have died in the shooting was taken into an ambulance in which medical personnel could be seen giving him cardio-pulmonary resuscitation. CBC News reported that he was a reservist who had been serving in Hamilton, Ontario.
Public Safety Minister Stephen Blaney said last Thursday the new legislation would let the agency track and investigate potential terrorists when they travel abroad and ultimately prosecute them.
Police and paramedics transport the wounded Canadian soldier on Wednesday in Ottawa. (AFP Photo)
Compared with Capitol Hill in Washington, security on Parliament Hill is also fairly low key. Anybody could walk right up to the front door of parliament's Centre Block with arms and explosives without being challenged before entering the front door, where a few guards check accreditation. The Canadian military closed its bases across the country following the events in Ottawa, CBC TV said.
They barricaded themselves in up in Canada's Parliament earlier today because of a shooter in the Ottawa Capitol. pic.twitter.com/dzftpaJkCH— Tom Odell (@TomOdell) October 22, 2014
With inputs from AFP, AP and Reuters