MONTREAL — The police on Monday morning moved in to break up a blockade at a rail station in Ontario by a group of Mohawks that has impaired 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 was set up along the Canadian National Railways by Mohawks 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 the Canadian economy from being damaged.
He was to meet with ministers on Monday, and the crisis was expected to top the agenda.
Both the provincial government of British Columbia and the elected leaders under Canadian law of the Wet’suwet’en First Nation in the province support the 416-mile pipeline project, which links gas wells in 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 in British Columbia 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.”
Bill Bair, the Minister of Public Safety, told the CBC, Canada’s national broadcaster, on Monday that the blockade was putting Canadians’ health and safety at risk and had to be ended. But he said the government remained committed to “addressing and redressing the concerns of Indigenous people.”
Mr. Trudeau and his cabinet have moved cautiously because of 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 on both sides. In Oka, a police officer died, and the Royal Canadian Mounted Police and the army moved in. A police officer was killed when the Ontario Provincial Police stormed protesters at Ipperwash.
In the latest protests, the greatest effect has come from the persistent blockade, which is actually a makeshift trackside camp, at Tyendinaga.
The political and economic effects of the camp far outstripped its modest scale, disrupting freight and passenger service in eastern Canada. While many passenger trains are again moving, there was still no service from Toronto to points east.
Andrew Scheer, the Conservative leader, has suggested that the protesters do not represent the majority opinion within Indigenous communities. He has also said that many protesters are non-Indigenous “radical activists” determined to ruin the oil and gas industry.
Dan Bilefsky reported from Montreal, and Ian Austen from Tyendinaga, Ontario.