Russia’s Black Sea Fleet is struggling to keep up “high profile public events” alongside its wartime activities, British defence chiefs have claimed.
Parades have been cancelled after the headquarters of the fleet in Sevastopol was the target of a strike on Navy Day, on Sunday.
The strike is “the latest setback” for the fleet in the war against Ukraine, which included the loss of its flagship vessel, the cruiser Moskva, in April.
“Following the reports of cancelled parades, it is unlikely that the Black Sea Fleet can manage high profile public events alongside its wartime activities,” the latest intelligence update from the Ministry of Defence said.
A senior official in Russia has accused Ukraine of carrying out the drone attack ahead of planned celebrations to mark Navy Day, injuring five and forcing the cancellation of festivities.
The accusation came hours before Russian President Vladimir Putin was due to oversee Navy Day celebrations in his hometown of St Petersburg on Sunday.
"An unidentified object flew into the courtyard of the fleet’s headquarters," Mikhail Razvozhayev, governor of Sevastopol, home to Russia’s Black Sea fleet, wrote on the Telegram messaging app.
"According to preliminary information, it is a drone."
He said Ukraine had decided to "spoil Navy Day for us".
"All celebrations have been cancelled for security reasons," Mr Razvozhayev said. "Please remain calm and stay home if possible."
Navy Day is an annual Russian holiday during which its fleets stage naval parades and honour its sailors.
It comes after the first grain ship left the Ukrainian port of Odesa since the invasion began.
The Sierra Leone-flagged cargo ship Razoni left Odesa headed for Tripoli in Lebanon loaded with 26,000 tonnes of Ukrainian grain after an agreement between Russia, Ukraine and Turkey.