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.