Bloomberg reported the information.A spokesperson for TMS Tankers said the explosion flooded the ship’s engine room. The vessel is now being towed to Greece. The cause of the blast is still unknown.The company also said the explosion caused no environmental damage and that the crew is safe.According to Bloomberg, the Vilamoura docked at Russia’s Ust-Luga port in early April to load Kazakh oil. In May, it was spotted at the Caspian Pipeline Consortium terminal near the Russian port of Novorossiysk, which mainly handles Kazakh oil as well.Marine risk consultancy Vanguard Tech said four other vessels have exploded since the start of the year — all had recently called at Russian ports. Since then, shipowners have started inspecting hulls for mines using divers and underwater drones.Vilamoura is part of Russia’s 'shadow fleet'This is according to Ukraine’s Main Intelligence Directorate.The agency said the incident occurred on June 27 while the tanker, sailing under the Marshall Islands flag, was traveling from Libya’s Ez-Zuwaitina port. The explosion happened 150 kilometers northeast of Libya’s territorial waters, in the engine room.“As of July 1, 2025, the fire-fighting tug Boka Summit, flying the Maltese flag, is towing the damaged Russian shadow fleet tanker to the Laconian Gulf in Greece for inspection,” the statement said.The vessel was loaded with at least 1 million barrels of crude oil. It is owned by TMS Tanker Ltd., a transport company registered in Marousi, Greece."Vilamoura has repeatedly carried oil products from Russian ports. For instance, it was seen at the Ust-Luga terminal in April 2025 and near Novorossiysk in May,” the intelligence added.On March 10, an oil tanker and a cargo ship collided in the North Sea off the UK coast, sparking a fire.