A Russian military ship fired warning shots at a British Royal Navy destroyer in the Black Sea, Russian news agency Interfax cited Russia's Defense Ministry as saying on Wednesday.
Russia said its border patrol ship fired the warning shots, while a SU-24 bomber dropped several bombs after a British Navy destroyer, the HMS Defender, violated Russian territorial waters.
"The destroyer had been warned that weapons would be used if it trespasses the border of the Russian Federation. It did not react to the warning," Russia's Defense Ministry said.
The HMS Defender left after shots were fired, the ministry said, accusing the UK of violating a United Nations convention on maritime law, Russian media reported.
After the incident, Russia's Defense Ministry summoned the UK's military attache, according to Russian news agency TASS.
UK denies Russia's claims
The UK's Defense Ministry said no warning shots were fired at the HMS Defender, arguing that it was in Ukrainian waters.
"The Royal Navy ship is conducting innocent passage through Ukrainian territorial waters in accordance with international law," the ministry said on Twitter.
The UK also said its ambassador to Russia had not summoned in Moscow.
UK Defense Minister Ben Wallace told lawmakers that he was not surprised by Russia's claims, saying that these things "come and go" with Russia.
Earlier this month, the Royal Navy said the HMS Defender had "peeled away" from its strike group conducting NATO operations in the Mediterranean to carry out "her own set of missions" in the Black Sea.
Dubbed "Sea Breeze," the military drills are due to start on Monday, with 32 countries on six continents sending 5,000 soldiers, 32 ships, 40 aircraft and 18 teams of special operations troops and divers.
Ukraine slams Russia's 'warning shots'
Ukraine's Foreign Minister Dmytro Kuleba said the incident showed Russia's aggressive and provocative policy.
"A clear proof of Ukraine's position: Russia's aggressive and provocative actions in the Black and Azov seas, its occupation & militarization of Crimea pose a lasting threat to Ukraine and allies," Kuleba said on Twitter.
"We need a new quality of cooperation between Ukraine & NATO allies in the Black Sea," he added.
Russian troop movements on the eastern Ukrainian borders had prompted fears of another military intervention, like in 2014 when Russia seized Crimea.
While incidents involving aircraft or ships are not uncommon at Russia's borders, they rarely result in open fire.