FORT MCMURRAY, Alta. - A Greenpeace protest at the massive Shell oilsands mine in northern Alberta ended peacefully Wednesday after 31 hours with an agreement that there will be no charges and no arrests.

"Shell has agreed not to pursue criminal charges against the protesters because it does nothing to further the climate change conversation," John Abbott, Shell's executive vice president of heavy oil, said in a news release.

About two dozen environmental activists from Canada, France and the U.S. snuck onto the property Tuesday morning and chained themselves to giant earth-moving equipment, raising questions about security.

The protesters placed giant banners on the ground reading, "Tarsands: Climate Crime."

Shell (NYSE:RDS.D) was forced to suspend operations at the Albian Sands mine for about six hours Tuesday, but work resumed later that day because of what the company called the respectful nature of the protesters.

Abbott said a full audit of security procedures and processes is underway at the mine and security has been significantly increased.

The protests were timed to coincide with a meeting Wednesday between Prime Minister Stephen Harper and U.S. president Barack Obama in Washington, D.C.

Mike Hudema, one of the Greenpeace leaders who chained himself an earth mover, said they wanted to send a message to world leaders on the environmental damage being caused by giant oilsands projects.

"Greenpeace will press world leaders to make strong commitments to fighting climate change, that means stopping the tarsands and embracing a clean energy future," he said.

A report released by Greenpeace earlier this week says greenhouse gas emissions from the oilsands will rival or exceed those of many European countries by 2020 and are already now greater than some medium-sized European countries.

Shell is working on reducing greenhouse gas emissions from its operations, the release said.

"We invited Greenpeace to discuss their climate and energy views with us directly but they chose not to do so, which is disappointing," Abbott said.

"Current and emerging regulations will drive us to reduce or offset greenhouse gas emissions from oil sands production to a level on par with competing crude oil alternatives," Abbott said. "That's our goal."

Another oilsands protest on the American side of Niagara Falls on Tuesday resulted in the arrests of five people in the Rainforest Action Network after a banner was hung with a similar message.