Thousands of protesters gathered in Canada's capital on Saturday to protest vaccine mandates, masks and lockdowns. 

Some parked on the grounds of the National War Memorial, others carried signs and flags with swastikas and the statue of a Canadian hero Terry Fox was defaced, sparking widespread condemnation. 

"Parking on this sacred ground that includes the Tomb of the Unknown Soldier was a sign of complete disrespect," Ottawa Mayor Jim Watson tweeted. 

Protesters compared vaccine mandates to fascism, one truck carried a Confederate flag and many carried expletive-laden signs targeting Canadian Prime Minister Justin Trudeau. 

The statue of the Fox, a national hero who lost a leg to bone cancer as a youngster, then set off in 1980 on a fundraising trek across Canada, was draped with a upside down Canadian flag with a sign that said "mandate freedom". 

Trudeau retweeted a statement from The Terry Fox Foundation that said "Terry believed in science and gave his life to help others." 

Canadian and Quebec flags are flown upside down as protesters participating in a cross-country truck convoy. Photo / AP 

David Santos said he came from Montreal because he believes the vaccine mandates are not health-related but what he calls a "control thing" by governments. 

The convoy of truckers and others prompted police to prepare for the possibility of violence and warn residents to avoid downtown. A top Parliament security official advised lawmakers to lock their doors amid reports their private homes may be targeted. 

Trudeau has said Canadians are not represented by this "very troubling, small but very vocal minority of Canadians who are lashing out at science, at government, at society, at mandates and public health advice″. 

The prime minister's itinerary for the day usually says he is in Ottawa if he's at home, but on Saturday it said "National Capital Region" amid a report he's been moved to an undisclosed location. 

Supporters wave flags on an overpass in Kanata, Ontario, Canada. Photo / AP 

Canada has one of the highest vaccination rates in the world and the premier of the province of Quebec who is proposing to tax the unvaccinated is popular. 

Some are, in part, protesting a new rule that took effect on January 15 requiring truckers entering Canada be fully immunised against the coronavirus. The United States has imposed the same requirement on truckers entering that country. 

The Canadian Trucking Alliance said a great number of the protesters have no connection to the trucking industry, adding they have a separate agenda to push. The alliance notes the vast majority of drivers are vaccinated. 

Protestors mingle around vehicles parked on Wellington St. in front of West Block and the Parliament. Photo / AP 

The organisers of the protest have called for the forceful elimination of all Covid-19 restrictions and vaccine mandates and some called for the removal of Trudeau. 

Some opposition Canadian Conservative lawmakers served coffee to the protesters including Michael Cooper, who did a live television hit while a person with a upside down Canadian flag with a swastika walked by. Conservative party leader Erin O'Toole met with some truckers. The protest has also attracted support from Donald Trump Jr and some Fox News personalities. 

"Today the threat against democracy isn't only happening in America," former US Ambassador to Canada Bruce Heyman tweeted. 

"Both the use of the swastika and the confederate flag are symbols of hate. So very sad to see these symbols anywhere and especially in Canada." 

The Parliamentary Protective Service expects as many as 10,000 protesters as part of a weekend-long rally. 

"I'm locked into my own country right now," said Tom Pappin, an unvaccinated man who came from just outside Ottawa. "I can't go on a holiday. I can't go to a restaurant, I can't go bowling. I can't go to a movie. You know, these are things that it's just gotten out of control." 

The 52-year-old said attendees are likely to stay parked by Parliament until vaccine mandates are lifted.