Russia's navy conducted test flights near the North Pole on Thursday, boosting its military presence in an area believed to contain vast quantities of oil and natural gas.
Cpl. Vladimir Serga, a naval spokesman, said that Il-38 anti-submarine bombers and Tu-142 long-range strategic bombers of the Northern Fleet took part in the exercise, in which the planes' crews tested radio and weapons systems management equipment.
Serga described the exercise as successful.
The flights come two days after a Russian missile cruiser began patrols in the Arctic.
The Marshal Ustinov, a nuclear-capable missile cruiser, was deployed Tuesday in the Arctic area "to provide for the safety of Russia's shipping industry," the navy said in a statement.
Russia has been increasingly assertive in the Arctic region as global warming makes the area's oil and natural gas resources more accessible. Last year Moscow sent an expedition to plant a Russian flag on the seabed under the North Pole.
On Wednesday the U.S. Geological Survey announced that the area north of the Arctic Circle might contain some 90 billion barrels of oil and a third of the world's undiscovered natural gas.
The survey required four years and is the most complete of the Arctic area ever undertaken.
In May five countries with competing claims to the Arctic — Russia, Denmark, Canada, Norway and the United States — agreed that control of the region where the polar melt is expected will be decided in an orderly way.