Via Rail has cancelled all Friday train services between Toronto and Montreal and between Toronto and Ottawa — even as the head of the Assembly of First Nations promised only "positive action" that day during a countrywide aboriginal rally.

Via said in a statement Thursday that the sudden cancellations were in anticipation of mass commuter chaos that could occur if some aboriginal activists followed up on their threat to blockade roads and railways on Friday — which the AFN designated as a National Day of Action to draw attention to aboriginal issues.

The rail company, which services 4.1 million passengers annually, said it would refund any tickets already purchased without penalties, while full service would resume by Saturday, once the rally is over.

Heading into the Canada Day long weekend, though, thousands of people could be scrambling to make alternative travel arrangements. 

Meanwhile, Assembly of First Nations National Chief Phil Fontaine urged First Nations communities and non-aboriginal people not to misinterpret the National Day of Action as an occasion for violent confrontation.

"Our position is very clear and we've stated this position over and over again: we believe in reaching out to Canadians, we want Canadians to join us, to walk with us, to accept First Nations people as an integral part of the country," he told reporters in Ottawa.

Fontaine acknowledged there is building resentment among First Nations about unresolved land claims, high-school dropout rates, poverty, low employment levels and high suicide rates in their communities.

He repeatedly stressed that the planned rally stretching from coast to coast was meant to be about educating the public and drawing attention to aboriginal issues — not illegal roadblocks.

The AFN "does not want to cause a major disruption in the lives of Canadians, we don't want to impede the Canadian economy, but we want Canadians to pay attention to our issues," he said.

Extra police to be deployed in Ontario

Ontario Provincial Police Commissioner Julian Fantino said the force would be dispatching extra officers "to ensure a peaceful outcome."

He told reporters that the public could brace for "some inconvenience," but added that for now, the OPP was in "wait-and-see mode."

Fantino said the force's top priority would be balancing the need to ensure public safety and respect for the rights of demonstrators.

He also assured motorists the OPP would be working to provide them with alternate routes in the event of traffic blockades.

CPR to halt trains in show of support

Holding up a letter addressed to Prime Minister Stephen Harper on behalf of the AFN, Fontaine said supporters of their cause could show their solidarity by filling out similar postcards urging the government to "close the gap" on native living standards.

In a more "complex and co-ordinated" show of support, Fontaine said Canadian Pacific Railway plans Friday to halt 300 freight trains across Canada for one minute starting at 2 p.m. ET.

"I think the decision taken by Canadian Pacific is honourable and it's very important gesture on their part," he said.

Fontaine said that a number of representatives of the House of Commons are expected to appear at a rally and march in Ottawa on Friday, including Liberal Leader Stéphane Dion and NDP Leader Jack Layton.

Fontaine said he would also extend an open invitation to any Conservative MPs to join the walk.