New Russian nuclear sub 'safer than Kursk'
The Russian navy has received a new nuclear missile submarine which has an escape capsule, to avoid any repetition of the 2000 Kursk disaster.
The Yuri Dolgoruky is the first of Russia's new Borei class of subs, with 16 intercontinental ballistic missiles on board. It has a crew of 107.
The construction cost was 23bn roubles (£472m; $757m). Russia plans to build eight more Borei subs by 2020.
In 2000 an explosion on the Kursk sub killed 118 sailors in the Arctic.
Russia's Vesti TV news says the Yuri Dolgoruky's escape capsule can accommodate the whole crew and float to the surface in an emergency.
The missiles in the on-board Bulava weapons system have multiple warheads and a range of more than 8,000km (5,000 miles).
The new sub was commissioned at the Arctic naval base of Severodvinsk. It is reported to be quieter than the fleet's existing subs and can dive to a depth of 450m (1,485ft).
Under Russia's military modernisation plans, costing nearly 4.5tn roubles, the navy will get 51 new warships and 24 submarines by 2020, Vesti reports.