Explosions were reported aboard an oil tanker suspected to be part of Russia’s “shadow fleet” while it was docked at the Russian Baltic port of Ust-Luga.

Russia’s Federal Agency for Sea and Inland Water Transport (Rosmorrechflot) confirmed an incident involving the Antigua and Barbuda-flagged oil tanker Koala. 

In a Telegram post, Rosmorrechflot stated that “an explosion took place in the engine room” of the Koala ship on Sunday morning.

The agency stated that the explosion did not cause “a spill of the cargo or a leak of oil products” and that there was no risk of the ship sinking. It also reported that the crew evacuated the vessel and that no casualties were recorded.

“The appropriate agencies are investigating the incident,” it added.

Despite the agency’s report that the tanker is not at risk of sinking, Russian sources, which claimed the explosion involved three separate blasts, said the explosions caused flooding in the engine room. The stern of the vessel settled onto the seabed at the pier but remained partially afloat.

🚨🚨🚨Yesterday, 9 February 2025, the oil tanker Koala suffered 3 💥💥💥explosions in its engine room as it was preparing to leave the seaport of 🇷🇺Ust-Luga, in the Leningrad area. The ship was carrying 130,000 tonnes of mazut.🛢️

This event highlights a series of technical… pic.twitter.com/bSOedxTXkI

— Russian Forces Spotter (@TiaFarris10) February 10, 2025

The Koala, a Suezmax tanker with a 160,000-deadweight tonnage capacity, is owned by a Turkish company and managed by a Cypriot firm. The vessel reportedly arrived at Ust-Luga on Thursday carrying approximately 130,000 tonnes of heavy fuel oil. 

The recent incident follows a series of maritime accidents in Russian waters. In December, two tankers carrying oil were wrecked in the Black Sea, causing an extensive spill. 

Meanwhile, in response to the potential environmental risks, Finnish Prime Minister Petteri Orpo announced that Finland has placed its oil spill response capabilities on alert as a precautionary measure.