European Union naval forces have boarded the tanker MV SUN in the Mediterranean, after the ship was suspected of being part of Russia's so-called "shadow fleet".

EU foreign policy chief Kaja Kallas announced that the operation was carried out on August 30 by forces from the EUNAVFOR MED Irini mission. According to her, the ship was suspected of sailing under a false flag, in violation of international maritime law.

"MV SUN, suspected of sailing under a false flag, was boarded to check its flag," Kallas stated in a post on the X platform.

Illegal oil sales from shadow fleet ships are a critical lifeline for Russia's war in Ukraine, and we'll continue to cut them off.

The oil tanker MV SUN, suspected of sailing under false flag in breach of international maritime law, was boarded on August 30 in the Mediterranean... pic.twitter.com/6HNcOYNcdh

— Kaja Kallas (@kajakallas) August 31, 2026

The EUNAVFOR MED mission Irini was established in 2020 to monitor and enforce the UN arms embargo on Libya. Over the years, its mandate has been expanded, giving European forces the ability to conduct inspections and board ships for documentation and flag verification.

The MV SUN case comes at a time when the EU has increased attention to the Russian "shadow fleet", consisting of ships suspected of being used to transport oil and circumvent Western sanctions.