Ukraine carried out a drone strike on a Russian tanker in the Kerch Strait, a source in the security service told AFP Saturday, a day after one of Moscow's ships was hit in the Black Sea.
This is the latest of the increasingly frequent attacks in the Black Sea since Moscow exited a deal last month that had allowed Ukrainian grain exports there.
"Overnight the (Ukrainian Security Service) SBU blew up the 'SIG', a large oil tanker of the Russian Federation that was transporting fuel for Russian troops," the security source said.
It added that the "successful special operation", which involved a naval drone and explosives, was carried out jointly with the Navy on Ukrainian territorial waters.
"It was well-loaded with fuel, so the 'fireworks' could be seen from afar," the source added.
Russian authorities said the SIG tanker was hit around 11:20 pm (2020 GMT) Friday south of the Kerch Strait.
The oil and chemical tanker is under US sanctions for supplying jet fuel to Russian forces in Syria supporting President Bashar al-Assad.
Russia's state RIA Novosti news agency said there were no casualties in the attack, citing the Maritime Rescue Coordination Centre of Novorossiysk.