A Russian tanker carrying LNG sank in the Mediterranean on Wednesday after what Moscow described as an attack by Ukrainian drones launched from Libya.
The Arctic Metagaz sank in waters between Libya and Malta after catching fire a day earlier, Libya's maritime rescue agency said in an advisory seen by Reuters.
"Information indicates that the tanker experienced sudden explosions followed by a massive fire, which ultimately led to its complete sinking," the agency said.
Ukraine has frequently targeted Russian oil refineries and other energy infrastructure in an attempt to deprive Russia's war machine of funding, but if confirmed, this would be its first attack on an LNG tanker.
The Security Service of Ukraine did not respond to a Reuters request for comment.
Russia's transport ministry said the tanker, which had been carrying LNG from the Arctic port of Murmansk, was attacked by Ukrainian naval drones launched from the coast of Libya.
It said the 30 crew members, all Russian nationals, were safe, and thanked Maltese rescue services.
"We qualify what happened as an act of international terrorism and maritime piracy, a gross violation of the fundamental norms of international maritime law," the ministry said.
Libya's National Oil Corporation said it had no involvement with the tanker, adding that it was en route to Port Said, Egypt.
The ship's Russia-based manager, LLC SMP Techmanagement, and Russian LNG producer Novatek have not commented on the incident.
The Libyan agency warned vessels to avoid the site and asked them to report any pollution in the area which one industry source said would likely be limited to the fuel oil on board.
(Reporting by Filipp Lebedev, Vladimir Soldatkin and Jonathan Saul; additional reporting by Ahmed Elumami in Tripoli; editing by Jan Harvey and Jason Neely)