US Navy Boeing P-8A Poseidon surveillance aircraft was intercepted by Russian Su-27 fighter over the Black Sea.

Defence officials claimed the Russian Su-27 fighters flew dangerously close to the US Navy P-8A Poseidon aircraft for 19 minutes yesterday as it was conducting routine operations in international airspace. Moscow has insisted the intercept was performed “in strict accordance with international flight rules”, with a defence ministry spokesman alleging the US aircraft had approached Russia’s southern border twice.

Independent monitors of air and sea traffic in the region indicated that a number of Russian ships were active near Ukraine’s Odessa offshore gas field while a US Navy P-8 was patrolling the same area. At least some of this airspace is understood to be claimed by Russia.

While photographs of the encounter have yet to be released, the stand-off is a reflection of the continued deterioration in relations between the United States and Russia since the latter’s annexation of Crimea and the ongoing crisis in eastern Ukraine. Last May another ‘unsafe’ intercept was reported over the Black Sea, involving a Russian Su-27 and a US Air Force RC-135 reconnaissance aircraft.

A month previous to that encounter, Russian Sukhoi Su-24 strike aircraft carried out a highly publicized series of low-level flights over the US Navy warship USSDonald Cook, under way in the Baltic Sea.