Cairn Energy has been forced to suspend its operations on one of its rigs in the Arctic after four Greenpeace campaigners scaled the rig early on Tuesday morning in a bid to stall oil drilling in the region.

The UK oil and gas explorer has plans to drill four wells in the waters of Baffin Bay Basin, off Greenland’s west coast, but the recent BP oil spill in the Gulf of Mexico has raised fears over the risks of offshore drilling.

Cairn announced last week that its first well had shown evidence of hydrocarbons.

A Greenpeace ship, the Esperanza, has been in a stand-off with the Danish navy off Greenland for the past few days. Many environmentalists argue that Arctic drilling is fraught with risks, from drifting icebergs to hostile weather, but as oil companies scramble to find new reserves around the world to meet demand its reserves have caught they eye of the industry.