(CNN) Protesters blocking Canadian railways have shut down large portions of the nation's passenger and freight train service this week, knocking out a travel option for thousands and spurring a business group to warn the cross-country flow of food and other goods will slow.

The protests started last week when police started arresting members of an indigenous group that was blocking a road to a construction site for the Coastal GasLink natural gas pipeline in British Columbia, CNN network partner CTV reported

Indigenous groups and allies blocked railways and government buildings around the country in solidarity with the British Columbia group. Some rail blockades have ended, but others remain, including near Belleville, Ontario.

Because of the remaining blockades:

• Canadian National Railway (CN) on Thursday said it's started to progressively shut down its eastern freight network, essentially east of Toronto.

• Passenger service VIA Rail, which largely uses CN railways, said Thursday it has suspended most of its runs across the country until further notice, after cancellations on a smaller scale earlier in the week.

"I got stuck here, basically," Amanda Viney, who was in Montreal on Thursday for a business trip, told CNN network partner CBC . "Now I'm going to attempt to catch a Greyhound back to Ottawa like everyone else."

Police officers stand on a road after clearing the intersection of protesters that were blocking an entrance to a port Wednesday in Vancouver, British Columbia. The demonstration expressed solidarity with Wet'suwet'en protesters who were arrested last week.

Near Belleville, a two-and-a-half-hour drive northeast of Toronto, activists with the Tyendinaga Mohawk group have placed vehicles near the tracks -- not across them, but too close for trains to safely pass, CBC reported

"This particular movement going across the nation around is so very important for the next generation," Pauline Maracle, who has been cooking for the camped-out protesters for a week, told CBC . "At the end of the day, it's the people for the people."

The initial pipeline protest in northern British Columbia involved the Wet'suwet'en Nation indigenous group, which opposes Coastal GasLink's plans to build a natural gas pipeline through their territory, CTV reported

Freight shutdown will restrict supplies of food and other materials, business group warns

CN and the Canadian Chamber of Commerce have called on the government to remove the rail blockades.

The rail company obtained a court injunction last week to end the Mohawk demonstration near Belleville, CBC reported, but police so far have not dispersed them.

CN has said the shutdown of its eastern network will halt all transcontinental freight trains across its network and may lead to temporary layoffs of operational staff.

Stopping those trains will "severely limit the movement of perishable foods and other consumer items, grain, construction materials and propane for Quebec and Atlantic Canada," the Canadian Chamber of Commerce wrote to two federal government ministers this week.

"This is creating tens of millions of dollars worth of economic damage today, right now," Ryan Greer, the chamber's senior director, told CTV Thursday.

"Until we have rail service resumed, I would say no level of government is fulfilling its duties to help uphold the rule of law and ensure that commerce can flow freely throughout our country," Greer said.

Ontario Provincial Police spokesman Bill Dickson, addressing the blockades that remain in his province after the court injunction, told CNN on Friday that the officers' goal is "a safe and peaceful resolution to this situation."

"The proper use of police discretion is a valid, appropriate approach to de-escalating situations such as this," Dickson said. "The proper exercise of police discretion should not be confused with a lack of enforcement."

He said the OPP will follow established policy for "indigenous critical incidents," which call for a measured and sensitive response.

"The OPP calls on those involved to abide by the court injunction and to not put public peace or anyone's safety in jeopardy," he said. "The OPP respects the right of everyone to freedom of expression and peaceful assembly, but we also recognize the rights of the general public, local residents and businesses to a safe environment."

People demonstrating in solidarity with the Wet'suwet'en Nation walk in downtown Vancouver, British Columbia, on Wednesday,

Prime Minister Trudeau acknowledges 'a really difficult week for Canadians'

Transport Minister Marc Garneau said he would meet Friday with representatives of indigenous organizations to discuss "a way forward."

"We are actively working for a ... resolution on all remaining blockades," he said

Prime Minster Justin Trudeau said the protests and rail disruptions amounted to a "really difficult week for Canadians."

"People (are) having trouble getting to work, to school or home, small businesses having trouble getting their goods to market, institutions like hospitals worried about resupply in ways that can really impact Canadians," Trudeau said Friday while attending the Munich Security Conference in Germany.

"We are a country that recognizes the right to protest, but we are a country of the rules of law," he said.