Police are making arrests at a protest site in Canada's capital which has been occupied by anti-vaccine mandate demonstrators for three weeks.
The operation started early on Friday morning in downtown Ottawa with police saying some protesters surrendered.
It comes days after the federal government invoked the Emergencies Act to crack down on demonstrations.
A group of protesters have remained in the city in defiance of orders to leave.
The police operation has so far remained peaceful.
"Freedom was never free," protester Kevin Homaund told the Associated Press. "So what if they put the handcuffs on us and they put us in jail?"
On Thursday, police detained two leaders of the trucker convoy. Tamara Lich and Chris Barber were both charged with mischief. Mr Barber also faces an obstruction charge.
Ottawa police set up almost 100 police check-points around the main protest site on Thursday, and a large business and residential district in the city centre to prevent more protesters from entering the area.
Canada's House of Commons and Senate cancelled Friday sittings because of police action surrounding the parliament buildings.
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Parliamentarians were scheduled to debate the decision by Prime Minister Justin Trudeau to invoke the never-before-used emergencies law.
The law grants government added powers in times of crisis and has been used to impose bans on public assembly in some areas of Ottawa and has prohibited travel to the protest zone, among other measures. What began in late January as a truck convoy headed to Ottawa to oppose a vaccine mandate for truckers crossing the US-Canada border grew into a broader opposition to pandemic restrictions and Mr Trudeau's government, with supporting protests across the country.
Authorities last weekend cleared the most economically damaging blockade - of a bridge linking Windsor, Ontario, with the US state of Michigan. Trucker protests at other border crossings in Coutts, Alberta, and Emerson, Manitoba, ended this week.
Many Ottawa residents have expressed frustration at local police, saying not enough was done to clear the protest, which has paralysed parts of the city around parliament and affected local businesses. The police chief resigned earlier this week over his handling of the demonstration.