Russia accused Britain's Royal Air Force (RAF) of intercepting its military aircraft over the Black Sea in a dangerous fashion designed to provoke Moscow after the RAF made two such interceptions in a single week.
The accusation, levelled by Russia's embassy in London, came after the RAF intercepted a Russian maritime patrol aircraft over the Black Sea on Friday and scrambled to intercept two suspected Russian fighter aircraft on Wednesday.
".... What kind of threat to Britain or even its allies does a Russian patrol aircraft hypothetically pose while conducting flights near Russia's own coastline, more than 2,000 km (1242.74 miles) from the British Isles," the Russian embassy said in a statement released on Saturday.
"Instead of strengthening anyone's security, the British authorities are using such a military presence (in the Black Sea area) for provocative actions. Not just by making verbal statements, regrettable as they are, but also in real military terms, which is simply dangerous."
The British defence and foreign ministries declined to comment on Sunday.
Three countries bordering the Black Sea - Romania, Bulgaria and Turkey - are NATO allies of Britain.
Britain's Minister of State for the Armed Forces, Mark Lancaster, spoke about "an ever more assertive Russia" in a speech in London in July. He said the RAF had been forced to intercept Russian military aircraft more than 80 times over the last decade.
Relations between London and Moscow are languishing at a post-Cold War low after the poisoning by nerve agent of former Russian double agent Sergei Skripal and his daughter Yulia in March in the English city of Salisbury.
London holds Moscow responsible for the attack, something Russia denies.
Britain's RAF maintains a presence in the Baltic countries and in Romania to deter potential Russian military action after Moscow's 2014 annexation of Ukraine's Crimea. Moscow says its activity in the Black Sea region is routine and compliant with international law.