Ukrainian drones hit a dozen more Russian tankers in the Sea of Azov overnight, Ukraine's military said on Thursday, the latest in a campaign aimed at disrupting fuel supplies to Russian forces and isolating Moscow-occupied Crimea.

Ukrainian drones struck eight sanctioned fuel tankers, a ferry and a cargo ship.

Ukraine's military said on Tuesday that its drones struck eight tankers from Russia's 'shadow fleet' overnight as they were delivering fuel to Crimea.