OSLO — Norway’s Coast Guard on Friday evening towed away a Greenpeace ship that tried to block a Norwegian company’s rig from drilling the world’s most northerly oil well, in the Barents Sea, the environmental group said.

Oil drillers from Norway are moving farther north as fields to the south are depleted and as the Arctic ice retreats, opening areas that were previously inaccessible. American estimates suggest that the Arctic may hold 13 percent of the world’s undiscovered oil and 30 percent of its gas.

“The Norwegian Coast Guard tonight boarded the Greenpeace ship Esperanza outside of the country’s territorial waters to end a high-profile and perfectly legal protest against Arctic oil drilling,” Greenpeace said in an emailed statement on Friday.

The group said two groups of officers boarded the ship and took control after the Greenpeace crew refused to leave.