Police are preparing to end a demonstration in Ontario by members of the Mohawks of Tyendinaga that has shut down traffic through one of Canada's busiest rail corridors.

Calling the situation "dire," Ontario Provincial Police (OPP) officers on Tuesday warned demonstrators set up along CN Rail tracks near Belleville, Ont., to clear the area or face a raid and arrests.

The demonstrators who met the officers said they would relay the message to the others.

The demonstration began Thursday in response to the RCMP's recent enforcing of a court order in B.C. on Wet'suwet'en camps built to block construction of the Coastal GasLink pipeline.

Via Rail said it has cancelled 157 trips on the Toronto-to-Montreal corridor by 8 a.m. Tuesday, forcing at least 24,500 passengers to change their travel plans

CN said the shut-down is also affecting shipments ranging from propane to feedstock, and has disrupted the only rail link between Eastern and Western Canada and the U.S. Midwest.

The demonstrators have not put any obstructions on the tracks but are set up near the rails — too close for trains to pass safely — near Belleville, about partway between Ottawa and Toronto.

The tracks run just outside the reserve boundary of Tyendinaga, but are within its claimed territory.

The Mohawks have said they won't leave until the RCMP have left Wet'suwet'en territory. The RCMP have finishing dismantling the camps, but remain to ensure compliance with the court order.

The warning was the second time on Tuesday liaison officers, who are specially trained to deal with First Nations protests, visited the demonstrators.

Earlier in the day, three OPP officers in civilian clothes stood across a fold-up table set up on the rail tracks by the demonstrators. The impromptu meeting followed an appearance by an Ontario Superior Court enforcement officer who was escorted by the OPP to read out a court order prohibiting continued interference with railway operations.

"You can't come here on our land and evict us off our land. You don't have the authority to do that," Kanenhariyo, a member of the Mohawks, whose English name is Seth LeFort, told officials.

The camp has grown over the past two days, with two new canvas tents pitched Monday evening and a steady flow of community members stopping by to express support or drop off supplies.

Kanenhariyo, who said he was not a spokesperson or a leader, only a community member, told the three officers that the decision to escort the court officer to read out the injunction and then attach it to one of the rail level crossings simply inflamed the situation.

Kanenhariyo, whose English name is Seth LeFort, speaks to the officers during a meeting on the train tracks on Tuesday. (Rozenn Nicolle/Radio-Canada)

On the table was a two-row wampum belt that symbolizes an agreement, dating to the 17th century, governing their interactions. Kanenhariyo said any resolution would require talks in the spirit of that agreement.

"There's agreements, and there is a process and protocol," he said.

OPP Sgt. Diana Hampson, the lead liaison officer, said the Mohawks had made their point and that they were heard.

"I know I would really like to go home and I wonder if you guys would maybe like to go home too, to your families," said Hampson.

"We are home," said one woman, standing next to Kanenhariyo.

"We are on our front lawn."

The OPP team also brought a gift of maple syrup.

"I don't know that we are in a place to have gifts at the moment," said Kanenhariyo.

"You did kind of come here to threaten us."