The submersible was taken to Severomorsk port after the incident (Library picture: Russian Ministry of Defence).
A fire on a Russian navy deep-sea submersible has killed 14 sailors.
Officials said the blaze broke out on Monday while the vessel was performing tests in Russian territorial waters.
It added that the fire was extinguished thanks to the crew's self-sacrifice, and the submersible is now at the Arctic port of Severomorsk, the main base of Russia's Northern Fleet.
The ministry statement said the submersible is intended for studying the seabed, but did not give its name or type.
"On July 1, fourteen submariners - sailors died in Russian territorial waters as a result of inhaling combustion products aboard a research submersible vehicle designated for studying the seabed space and the bottom of the World Ocean in the interests of the Russian Navy after a fire broke out during biometric measurements," the statement said.
Authorities have not given a cause for the fire, but an official investigation has been launched.
The Russian navy uses Priz-class and Bester-class deep water vehicles, which have hulls built of titanium and are capable of operating at a depth of 1,000 metres.
They are transported to the area of operation by a carrier vessel and can operate autonomously for up to 120 hours.
It is the deadliest Russian naval incident since 2008, when 20 died as a firefighting system was accidentally initiated while the Nerpa nuclear-powered submarine of Russia's Pacific Fleet was undergoing trials.
In the deadliest naval incident in post-Soviet Russia, the Kursk nuclear submarine exploded and sank on August 12 2000, during naval manoeuvres in the Barents Sea, killing all 118 crew members.