Britain rejected Russia's account of the incident, saying it believed any shots fired were a pre-announced Russian "gunnery exercise," and that no bombs had been dropped. But it confirmed that its destroyer, HMS Defender, had sailed through what it described as waters belonging to Ukraine.
The ship was "conducting an innocent passage through Ukrainian territorial waters in accordance with international law," Britain's Ministry of Defense said in a statement.
Prime Minister Boris Johnson's spokesman said: "It's incorrect to say either that it was fired upon or that the ship was in Russian waters."
Military experts said that whether or not the details of the Russian or British accounts were accurate, the incident appeared to represent an escalation in confrontation between the West and Russia over disputed sea lanes.