Explosions and smoke reported in Severomorsk, Russia — home port for nuclear-armed submarines.

NEW: Explosions and smoke reported in Severomorsk, Russia — home port for nuclear-armed submarines.

It is the main base of the Russian Northern Fleet, on the Kola Bay near the Barents Sea.

Hosts two-thirds of Russia’s nuclear-powered subs, including Yasen, Oscar II, Sierra II, and special-purpose subs.