The environmental group said two of its activists were arrested and taken into Russian Coast Guard custody after scaling a drilling platform in the Russian arctic. Greenpeace was in the area with its Arctic Sunrise protest vessel to campaign against Gazprom's operations in the northern Pechora Sea.
Gazprom's Prirazlomnaya rig was towed to the region last year as the first ice-resistant oil rig in the world.
Ben Ayliffe, advocacy director for Greenpeace, said the Russia Coast Guard fired 11 warning shots at protesters and threatened to fire on the Arctic Sunrise if the group didn't halt its activity.
"Let's be absolutely clear about this: the real threat to the Arctic comes not from Greenpeace International but from oil companies like Gazprom that are determined to ignore both science and good sense to drill in remote, frozen seas," he said in a statement.
There was no statement available from Russian authorities or Gazprom. Energy officials were quoted last month by The Moscow Times as saying emergency response crews "work night and day" and "were trained under a dedicated program for emergency response and first aid in case of sea accidents" in the remote environment.