Rail lines across Canada have been paralysed for almost two weeks after being blockaded by indigenous protesters and their supporters.
The blockades were put in place in solidarity with Wet'suwet'en First Nation hereditary chiefs who oppose a natural gas pipeline in their traditional territory in the province of British Columbia (BC).
The conflict began after police enforced a court injunction to clear Wet'suwet'en camps blocking a road leading to a work site for the pipeline.
The economic impact of the rail blockades is beginning to be felt across industries and there are concerns about shortages of goods.
Canadian Prime Minister Justin Trudeau is under growing pressure to solve the conflict as trains remain idle.
So what's at the core of the dispute?
What is the background?
The Coastal GasLink pipeline is a 670km (416 miles) project that would ship natural gas from north-eastern parts of BC to the coast.
The C$6.6bn ($4.9bn, £3.8bn) project, in a remote part of the province a full day's drive from Vancouver, has been in the works since 2012.
While the conflict is in part over opposition to the pipeline project, it is also about broader complex issues like indigenous governance, indigenous rights, and reconciliation.
Coastal GasLink has reached deals with 20 elected indigenous councils along the route, including some Wet'suwet'en councils.
Training, employment, and community investment forms part of the agreements.
But Wet'suwet'en hereditary chiefs oppose it and claim they hold authority over a bigger expanse of traditional lands, not just reserve land, over which the elected councils have no jurisdiction.
It's not clear exactly how much support - or lack of support - there is within the broader Wet'suwet'en community for the pipeline, though some have told the media the community is split.
For years, protesters have erected camps along the proposed pipeline route to prevent access to construction sites.
In early February, Royal Canadian Mounted Police (RCMP) enforced a court injunction and cleared the camps, arresting people in the process.
Meanwhile, other blockades and protests have sprung up across the country in solidarity with Wet'suwet'en hereditary chiefs, disrupting rail lines, ports and highways.
What has been the response?
The prime minister and indigenous leaders say peaceful, respectful dialogue is the best path forward.
Opposition Conservative leader Andrew Scheer has accused Mr Trudeau of having "no plan whatsoever" to resolve the conflict.
Assembly of First Nations National Chief Perry Bellegarde has met the parties involved and other indigenous leaderships across Canada and has said "we want to de-escalate and we want dialogue".
Minister of Crown-Indigenous Relations Carolyn Bennett has sent letters to Wet'suwet'en hereditary leadership saying she is open and available "at the soonest opportunity" for a meeting. She is awaiting a response.
One key request by Wet'suwet'en hereditary leadership is for the RCMP to leave their traditional territories, and on Thursday, the force offered to do so.
What is the economic impact?
Last week, Canada's CN Rail said it was forced to shut down its eastern network, which will effectively stop all cross-country freight trains.
CN transports more than C$250bn ($188bn; £145bn) worth of goods annually across Canada.
It has obtained court injunctions to clear some blockades, but police have so far refrained from using force to uphold it.
Over 94,000 passengers have already been forced to find alternative means of travel since the passenger trains stopped running, though some passenger rail service is returning this week.
Passenger service Via Rail has announced 1,000 temporary layoffs and CN announced 450 temporary layoffs notices.
We have NOT MET with @Carolyn_Bennett or with @scottfraserndp. We will not talk to them until the RCMP are out of our lands and until CGL permits are pulled and they adhere to our eviction notice. https://t.co/ELnKakxYHP— Smogelgem (@smogelgem) February 18, 2020
Industry groups say the impact is already being felt throughout the supply chain.
What about indigenous rights and reconciliation?
Mr Trudeau and his Liberal party came to power promising to transform the country's relationship with Indigenous people.
But his government's support for some major energy projects have become flashpoints amid those reconciliation efforts.
While a number of First Nations communities have chosen to participate in the oil and gas sector and have even backed some contested projects, others have helped drive opposition to controversial energy infrastructure projects.
That includes the Coastal GasLink project.
Indigenous leaders say this current conflict is a critical moment for the prime minister to show his government is genuine and sincere about moving ahead with reconciliation.
In Canada, indigenous people have rights that include the right to land, to self-determination and self-government, and to practise their culture and customs.
Canada also has a duty to consult with indigenous peoples before they begin any projects on their land, a responsibility sometimes relegated to companies.
Indigenous rights expert Dayna Scott says the rules around consultation are not entirely settled.
"It's a very complex area of law that's changing all the time," Ms Scott told the BBC.
"It's unsettled what we should do in a situation like this where [those seeking consent] disagree with the hereditary leaders and so indigenous leaders there will say they haven't obtained consent from the appropriate authorities."
Another issue raised by this conflict is over land.
"It's a question of whose land it is and who has a decision-making authority over it, and does a Crown really have uncontested, exclusive title to all the land within its borders," says Ms Scott.
Adding to the complexity is the United Nations Declaration on the Rights of Indigenous Peoples, which states that Indigenous peoples should have "free, prior and informed consent" on a project that may affect them or their territories, says Ms Scott.
That declaration has been endorsed - but not adopted by Canada - while BC is the first jurisdiction in the country to pass legislation to ensure laws are consistent with the declaration.
There are over 1.6m indigenous people in Canada, which includes First Nations, Inuit, and Metis, and they make up about 5% of the national population.