Russian police detained two dozen Greenpeace activists on Tuesday for protesting against Arctic drilling after Russia\'s largest oil producer signed a landmark deal with Exxon Mobil Corp to jointly prospect for oil in the far north. A spokeswoman for the environmental group, Vera Bakasheva, said a total of 23 activists were arrested for holding an unsanctioned rally outside Russia\'s Arctic Oil and Gas Conference in Moscow. \"We wanted to give the message to the people at the conference that drilling in the Arctic is dangerous and needs to be stopped,\" Bakasheva said. The protest was organized after Rosneft and Exxon earlier this week sealed a wide-reaching partnership granting both sides access to each others\' reserves. The deal paved the way for both companies to prospect for oil in three areas of Russia\'s Arctic Kara Sea, estimated by Rosneft to hold 36 billion barrels of recoverable reserves. Rosneft, Russia\'s largest oil producer, is relying on the Arctic\'s vast resources for future growth in order to achieve its long-term goal of sustaining output at above 10 million barrels per day as its oil-producing heartland of Western Siberia begins to yield less. But environmental groups fear exploration will disrupt the region\'s fragile ecosystem. In particular, they worry that the Arctic conditions - its remoteness, sub-zero climate, ice and high winds - could make a potential spill disastrous. Activists, who held banners proclaiming \"Save the Arctic\" and \"Don\'t Invest in Arctic Destruction,\" face fines of up to 1000 roubles ($34) at a hearing set for Monday, said Bakasheva. Greenpeace presented a report to Russia\'s parliament last year, asking its lawmakers to help prevent Arctic drilling by oil companies such as Gazprom and Shell.