An unidentified protester sits on a conveyer belt in this image from Greenpeace's live video stream of its protest at Suncor's mine in northern Alberta. (Greenpeace)

Up to 10 Greenpeace activists were arrested after stopping their boats on the shore of the Athabasca River on Wednesday afternoon, as part of a blockade at Suncor Energy's open-pit mine in northern Alberta, a Greenpeace spokeswoman said.

One group of protesters floated a large banner on the river that said 'Dying for Climate Leadership,' while another group went ashore and stopped two Suncor conveyer belts that carry oilsands material to a nearby upgrader.

Jessica Wilson, one of the protesters taken into police custody, said the "water team" had stopped at the east bank of the river, three kilometres north of the Suncor site, when police approached them.

"We stopped over just to kind of refill our boat just a little bit and the police and fire department came over and told us that if we didn't leave and get back in our boats we'd be charged with trespassing, as it was a Suncor site," Wilson said.

"We said 'OK, we'll go,' and we started to get back in our boats and then they rushed in and just nabbed us all.

"I was removed fairly forcefully from my boat," Wilson added, saying she expects to be charged with mischief.

Fort McMurray RCMP could not be reached immediately for comment.

Some protesters remain on site

Wilson said about 11 activists, who are part of the "conveyer team," have remained on the heavy equipment at the Suncor site.

"We have a number of activists, many of them international activists — some from Brazil, Germany, France — who have occupied two of the conveyer belts out at the site," Bruce Cox, executive director of Greenpeace Canada who is at the protest, said earlier Wednesday.

A spokesperson for Suncor confirmed the company had stopped the conveyer belts but said the facility continued to operate.

"Given the size and scale of our operations, there is some flexibility built into how we operate," said Sneh Seetal. "There might be some minor short-term impact."

Suncor has offered to speak to the protesters, Seetal said.

"To date, Greenpeace has not taken us up on that offer. For the near term, our focus is on ensuring the safety and respectful treatment of activists and staff alike."

A world message

But Cox said individual companies are not the main target of Tuesday's protest.

"We want to get a message to world leaders," he said. "We're less than 70 days out from the critical UN climate talks in Copenhagen and they have to get serious about cutting greenhouse gas emissions."

The blockade, which began Tuesday, is the second protest mounted by Greenpeace against the Alberta oilsands within a month.

On Sept. 15, protesters chained themselves to two massive oilsands trucks after sneaking on to Shell Canada's Ablian Sands mine, an action timed to coincide with a meeting the following day in Washington between Prime Minister Stephen Harper and U.S. President Barack Obama.

That protest ended peacefully the next day after Shell and the RCMP agreed to let the protesters leave without being charged.