Protesters with the Idle No More movement in Manitoba targeted railway lines and highways as part of a national day of protest on Wednesday.

A protest on the CN Rail crossing near the intersection of the Trans-Canada Highway and the Yellowhead Highway near Portage la Prairie, Man., prompted the railway company to obtain a court injunction.

Idle No More protesters from Berens River march in downtown Winnipeg on Wednesday as part of a national day of action. (Meagan Fiddler/CBC)

More than a dozen demonstrators waved placards at a freight train early that morning, then took over the crossing, forcing another train to be halted by police at the scene.

Service was stopped as of noon CT on the blocked rail line, which CN Rail spokesman Jim Feeny describes as a "critical link" in its network.

The group of protesters heckled the officers who served the court injunction at the blocked rail line on Wednesday afternoon.

CN Rail officials said the injunction meant the protesters must leave the rail line or face arrest, but the demonstrators initially said they would stay put, even if that meant they could be arrested.

"This is going to be permanent. We're not going away," said Morris St. Croix, one of the demonstrators.

"We're gonna dig in until [Prime Minister Stephen] Harper hears what we got to say to him."

After the court injunction was given to the group, some of the demonstrators left.

Four protesters who remained blocked the Yellowhead Highway late in the afternoon, but they left the area by 6 p.m.

Blockade at Manitoba-Ontario border

Another group of Idle No more protesters blocked the Trans-Canada Highway near the Manitoba-Ontario border for several hours Wednesday afternoon.

Members of two First Nations from the Shoal Lake area began blocking the highway at around 1 p.m. CT, backing up traffic for some distance in both directions. The protest ended by 4 p.m.

Terry Nelson and other demonstrators wave placards at a CN freight train near the intersection of the Trans-Canada Highway and the Yellowhead Highway on Wednesday. (Claudine Richard-Beaudoin/CBC)

During the protest, Ontario Provincial Police kept one lane of traffic open to ease the congestion.

In Winnipeg, dozens of protesters marched downtown, starting at Portage Avenue and Memorial Boulevard, and gathered on the steps of the Manitoba legislative building.

The group consisted mostly of members of the Berens River First Nation, who drove to 400 kilometres to Winnipeg Wednesday morning, despite the cold and treacherous ice road conditions.

"Crossing the lake, the lake is not really open yet, so it was a bit of an exciting ride across," said Joan Jack, a band councillor and organizer of the march.

She said sanitation and education facilities at Berens River are substandard and it's worth making the long trip to let people know about the conditions.

Many other cities across Canada are bracing for serious traffic disruptions and possible blockades as part of the grassroots movement, which opposes changes to Bill C-45, the Conservative government's controversial omnibus budget bill, that directly affects First Nations communities.

Trains halted

During the Portage la Prairie blockade, all trains through the area were stopped, according to CN spokesman Jim Feeney.

Protesters gather on the rail crossing following the passing of a freight train on Wednesday. (Claudine Richard-Beaudoin/CBC)

"We are taking the necessary steps to protect our employees, customers and facilities," Feeny told CBC News early Wednesday afternoon.

"We have stopped train traffic in the immediate area and have obtained a court injunction."

The blockade was conducted by a group of protesters headed by Terry Nelson, a former chief of the Roseau River First Nation.

He said the protest aims to educate Canadians about aboriginal treaty rights and land disputes First Nations people have with governments.

"We're sending the message very clearly with the railway blockade that [there's] going to be no more stolen property being sold until such time that they come to the table and deal with the original owners," he told CBC News on Tuesday.

Nelson said the approximately 15 protesters who are with him are willing to be arrested if that's what it takes to get their message known.

"We're very clear — we're going to do the blockade and whatever arrests, whatever happens … we're doing the Manitoba part of a national action," he said.

"If and when the people that are on the … railway blockade get arrested, other people will take their place," he said.

Chief opposes use of force

Derrick Gould, an organizer of a protest at the Fairford First Nation, told CBC News hundreds of people were planning to block traffic on Highway 6 at the bridge near the Fairford dam.

Meanwhile, Grand Chief Derek Nepinak of the Assembly of Manitoba Chiefs says he worries some protesters might take things too far.

"I think it's very important to recognize that we do not, at this time, condone the use of any kind of force," Nepinak said.

"We can't win in any kind of environment where we're using force."

The Idle No More movement, which began in November and quickly spread across the country through rallies and social media, stemmed from discontent among First Nations people over the federal government's general stance on indigenous rights.

Idle No More participants have taken issue specifically with Bill C-45, which they say erodes the rights of native people. They also argue there has been a lack of consultation on changes to environmental protection regulations.

A number of rallies have been held in Manitoba in recent weeks, including several events last Friday.