U.K. Says Russia Relocated Black Sea Submarines As 'Threat Level' Rose From Ukrainian Attacks

Two Russian cruise-missile submarines are shown moored in Sevastopol in June.

British defense intelligence has said in its latest assessment that it believes Russia's Black Sea Fleet has moved submarines from their home port on the annexed Crimean Peninsula to southern Russia in a sign of the increased threat to Russian forces of Ukraine's "long-range strike capability."

The British Defense Ministry said in its intelligence update that the Black Sea Fleet's command "has almost certainly relocated its KILO-class submarines" from the waters off Sevastopol to Novorossiisk in the Krasnodar region.

"This is highly likely due to the recent change in the local security threat level in the face of increased Ukrainian long-range strike capability," it said.

It cited attacks in the past two months on the Russian fleet's headquarters and its main naval-aviation airfield.

The British update said Russian President Vladimir Putin had thus undercut one of his main "motivations" for occupying and annexing Crimea from Ukraine in 2014 -- to provide a safe base for the fleet.

"Base security has now been directly undermined by Russia's continued aggression against Ukraine," the ministry said.