The environmental group Greenpeace has blocked an offshore drilling operation near Greenland. On Tuesday, four activists boarded and locked themselves to an oil rig owned by the company Cairn Energy. Speaking from the activists’ ship, Greenpeace campaigner Leila Deen criticized Cairn for drilling in the Arctic.

Leila Deen: “At 6:00 a.m. this morning, we launched three boats, evaded the Danish navy and the police that are surrounding the Stena Don drill rig, to occupy it with a bunch of climbers. Now we’re here because Cairn Energy is drilling in the Arctic. It’s an incredibly dangerous place to be drilling, and Cairn has no response for drilling here in the Arctic.”

The activists say they have enough supplies to remain aboard the rig for several days. Greenpeace says it’s hoping to disrupt Cairn’s operations before a winter deadline to complete its Arctic drilling.