Reportedly critical drone strike is first in Mediterranean since full-scale invasion began as maritime conflict grows

• ‘There are hundreds’: tracking Russia’s ‘shadow fleet’ of oil tankers

Ukraine says it has attacked a Russian “shadow fleet” tanker with aerial drones 1,250 miles (2,000km) from its borders, in the first such strike in the Mediterranean Sea since Moscow’s full-scale invasion nearly four years ago.

Friday’s strike off the coast of Libya, which reportedly caused critical damage, took place on the day of Vladimir Putin’s annual end of year press conference in which he said Russia would respond to recent Ukrainian attacks on shadow fleet tankers.