More than 100 people have been arrested in Ottawa after police began clearing out truckers who have paralysed the Canadian capital for three weeks in a protest against the country’s Covid-19 restrictions.

Those arrested had mostly been detained on mischief charges, and nearly two dozen vehicles had been towed, including all of those blocking one of the city’s major streets, authorities said.

Interim Ottawa Police chief Steve Bell said one officer had a minor injury, but no protesters had been hurt.

Police “continue to push forward to take control of our streets”, he said, adding: “We will work day and night until this is completed.”

Those arrested included four protest leaders. One received bail while the others remained jailed.

The crackdown on the self-styled Freedom Convoy began in the morning, when hundreds of police, some in riot gear and some carrying automatic weapons, descended into the protest zone and began leading demonstrators away in handcuffs through the snowy streets as holdout truckers blared their horns.

Tow truck operators — wearing neon-green ski masks, with their companies’ decals taped over on their trucks to conceal their identities — arrived under police escort and started removing the hundreds of big rigs, campers and other vehicles parked shoulder-to-shoulder near parliament.

Scuffles broke out in places, and police repeatedly went nose-to-nose with the protesters and pushed the crowd back amid cries of “freedom” and the singing of the national anthem. Later, police on horses were used to push back the crowd for a time.

Police said late in the afternoon that protesters had assaulted officers and tried to take their weapons. Some began dismantling equipment at a stage where they had played music for weeks, saying they did not want it to get destroyed.

Many protesters stood their ground in the face of one of the biggest police enforcement actions in Canada’s history, with officers drawn from around the country.

“Freedom was never free,” said trucker Kevin Homaund, of Montreal. “So what if they put the handcuffs on us and they put us in jail?”

But a steady procession of trucks began leaving Parliament Hill in the afternoon.

Police would not disclose how many protesters or vehicles remained downtown. All indications were that police would be working into the weekend to clear the area.

The capital and its paralysed streets represented the movement’s last stronghold after weeks of demonstrations and blockades that shut down border crossings into the US and created one of the most serious tests yet for prime minister Justin Trudeau. They also shook Canada’s reputation for civility, with some blaming America’s influence.

Authorities had hesitated to move against the protests, in part because of fears of violence. The demonstrations have drawn right-wing extremists and veterans, some of them armed.

With police and the government facing accusations that they let the protests get out of hand, Mr Trudeau on Monday invoked Canada’s Emergencies Act. That gave law enforcement extraordinary authority to declare the blockades illegal, tow away trucks, arrest the drivers, suspend their licenses and freeze their bank accounts.

Ottawa police made their first move to end the occupation late on Thursday with the arrest of two key protest leaders. They also sealed off much of the downtown area to outsiders to prevent them from coming to the aid of the protesters.

The emergency act enabled law enforcement authorities to compel tow truck companies to assist. Ottawa Police said earlier that they could not find tow truck drivers willing to help because they either sympathised with the movement or feared retaliation.

The Freedom Convoy demonstrations initially focused on Canada’s vaccine requirement for truckers entering the country but soon morphed into a broad attack on Covid-19 precautions and Mr Trudeau’s government.

Ottawa residents complained of being harassed and intimidated by the truckers and obtained a court injunction to stop their incessant honking.

Mr Trudeau portrayed the protesters as members of a “fringe” element. Canadians have largely embraced the country’s Covid-19 restrictions, with the vast majority vaccinated, including an estimated 90% of the nation’s truckers.

Some of the vaccine and mask mandates imposed by the provinces are already falling away rapidly.