Two sailors have been wounded after two artillery boats were hit in the strikes, the Ukrainian navy said.

Ukrainian president Petro Poroshenko has called an emergency session of his war cabinet after a day of rising tensions off the coast of Crimea.

A statement from Ukraine’s ambassador to the UK said Russian special forces had captured three ships in an “act of aggression”.

“According to the Ukrainian navy, Russia opened fire at small-sized ‘Berdiansk’ and ‘Nikopol’ armoured artillery boats,” the statement said.