"Up to 10 submarines are conducting various missions around the globe, including training and combat patrol missions with nuclear weapons on board," the source said, adding that most of them are from the Northern and the Pacific fleets.
The Russian Navy maintains a fleet of 60 nuclear-powered and diesel-electric submarines in active service, including 10 nuclear-powered strategic submarines, over 30 nuclear-powered attack submarines.
Under a new military doctrine, the nuclear triad of ballistic missiles, nuclear-powered submarines and strategic bombers will remain the core of the Russian armed forces for the next two decades.
"The Navy General Staff believe that strategic submarines will continue playing an important role in safeguarding Russia's national security because they remain one of the key components of Russia's military might and serve as a reliable deterrent to potential threats and aggression against the country," the Navy source said.
Russia has recently started mooring trials of the first Borey class nuclear-powered strategic submarine, which will be equipped with Bulava sea-based ballistic missiles.
The Yury Dolgoruky submarine, built at the Sevmash plant in northern Russia, was taken out of dry dock in April 2007.
The vessel is 170 meters (580 feet) long, has a hull diameter of 13 meters (42 feet), a crew of 107, including 55 officers, maximum depth of 450 meters (about 1,500 feet) and a submerged speed of about 29 knots. It can carry up to 16 ballistic missiles and torpedoes.
Two other Borey class nuclear submarines, the Alexander Nevsky and the Vladimir Monomakh, are currently under construction at the Sevmash shipyard and are expected to be completed in 2009 and 2011. Russia is planning to build a total of eight submarines of this class by 2015.
In addition, a fourth-generation Graney class nuclear-powered attack submarine will be delivered to the Russian Navy in 2010-2011. The Severodvinsk submarine combines the ability to launch a variety of long-range cruise missiles (up to 3,100 miles) with nuclear warheads, and effectively engage hostile submarines and surface warships.
The second submarine of this class is expected to enter service by 2015.
Russia is planning to completely modernize the naval component of its nuclear triad by 2016.