Russia has alleged that Ukraine has carried out a "massive" drone attack on the Black Sea Fleet in the Crimean port city of Sevastopol on Saturday, damaging one warship, reports BBC.
In the attack, nine drones were used, a top official said. Russia has replied by launching large-scale attacks on Ukrainian infrastructure, particularly on the country's energy grid.
Ukraine, however, has not commented.
Russia accused British troops of being involved in Saturday's attack - and in blowing up gas pipelines last month.
In its response, the UK Ministry of Defence (MoD) said Russia was "peddling false claims of an epic scale".
Russia said the ships targeted in the attack were involved in the internationally-brokered deal to allow grain exports from Ukrainian ports and hours later announced that it was suspending its participation in it.
The attack comes as Ukrainian troops successfully retake territory occupied by Russian troops since they launched their invasion on February 24.
Bd-pratidin English/Golam Rosul
