MONTREAL — The police on Monday morning moved to break up a blockade near a rail crossing in Ontario by an Indigenous group that has disrupted passenger and freight trains in Canada, stoked fears about fuel shortages and layoffs, and created a tricky political challenge for Prime Minister Justin Trudeau.
The blockade had been set up along Canadian National Railways tracks by members of the Tyendinaga Mohawk Territory in support of Indigenous groups who oppose a natural gas pipeline in British Columbia. Dozens of police officers moved in on the protest, in Tyendinaga, Ontario, east of Toronto, after the disruption lasted more than two weeks.
The Ontario police said that several people had been arrested and that the use of force was a “last resort.”
The protest has affected rail travel for at least 103,000 Canadians and prompted temporary layoffs. The government-owned Via Rail Canada, which mostly runs on Canadian National’s tracks, at one point shut down all passenger trains in the country and temporarily laid off 1,000 employees.
Mr. Trudeau, who has made reconciliation with Indigenous people a cornerstone of his premiership, has been at pains to prevent the conflict from escalating into violence. But the blockade put him in a difficult spot as he has sought to address Indigenous concerns while trying to prevent damage to the Canadian economy.
The 416-mile pipeline project has the support of both the provincial government of British Columbia and the elected leaders under Canadian law of the Wet’suwet’en First Nation in the province. The project links gas wells within British Columbia to a new liquefied natural gas terminal on its coast.
The pipeline is opposed, though, by hereditary leaders of the Wet’suwet’en First Nation, who have been trying for more than a year to stop the pipeline from being laid through a portion of their land.
What started as a modest protest by a small group of Mohawks ballooned into a series of nationwide disruptions of various sizes and duration. Traffic was snarled in cities, ports were cut off and British Columbia’s legislature was effectively closed off.
While some of the protests mainly involved Indigenous groups, many have included non-Indigenous people who appeared to be acting more in opposition to energy pipelines generally than in sympathy with the Wet’suwet’en land claims.
Mr. Trudeau initially responded by calling for patience from Canadians as the government tried to negotiate a peaceful solution.
By Friday, however, even Mr. Trudeau’s patience had run out. He said Indigenous leaders had not responded to government efforts to resolve the crisis, which was leading to increasing concerns about the potential for broader economic effects.
In what was widely seen as an invitation for the police to move in, the prime minister said on Friday that “the barricades need to come down now.”
Mr. Trudeau and his cabinet have moved cautiously to try to maintain the country’s reconciliation efforts with Indigenous people. Looming over the crisis have been memories of earlier protests by Indigenous people that escalated into violence.
In the 1990s, efforts by the police to end land occupations at Oka, Quebec, and Ipperwash, Ontario, led to protracted standoffs and deaths. In Oka, a police officer died, and the Royal Canadian Mounted Police and the army moved in. A protester was killed when the Ontario Provincial Police stormed protesters at Ipperwash.
Andrew Scheer, the Conservative leader, said in Parliament on Monday that Mr. Trudeau had caved in to “radical activists” and had equivocated too long before acting, showing weakness and fear.
“It shouldn’t take 19 days,” to enforce the law, he told reporters in Ottawa, saying the “illegal” blockade had crippled vital services, scared away investment by creating the perception that Canada is unstable and resulted in propane shortages and in layoffs.
Mr. Scheer has previously suggested that the protesters do not represent the majority opinion within Indigenous communities.
Mr. Trudeau, though, told Parliament on Monday that the government had been determined to find a peaceful solution to the blockade. He said that once his government thought it was clear that the protesters weren’t prepared to negotiate in good faith, the government took action.
The protests have become wrapped up in a wider debate in Canada pitting environmental interests against the economic imperative of the country’s energy industry.
The Canadian mining company Teck Resources on Sunday announced it was withdrawing from plans to build a large oil sands mine in Alberta, citing debates about global warming in Canada. The project would have created 7,000 construction jobs, according to the company.
Turning to Twitter to express his disappointment over the weekend, the premier of Alberta, Jason Kenney, partly blamed the decision on “the current lawless opposition to resource development.”
Dan Bilefsky reported from Montreal, and Ian Austen from Tyendinaga, Ontario.