Authorities in Greece are investigating an armed unmanned surface vessel that washed ashore on an island off the country’s western coast, according to Greece’s public broadcaster, ERT.

The broadcaster said a fisherman on the island of Lefkada found the craft inside a coastal cave on Thursday and towed it to a nearby harbor. ERT reported that the vessel was later moved on Friday to a naval base on the mainland for inspection.

Greek authorities have not confirmed where the vessel originated, according to the report. The investigation centers on determining the craft’s origin and what it is capable of, including whether it matches equipment associated with current drone warfare in the broader region.

The report said Ukraine has used drone boats in the Black Sea to target Russian naval vessels, while Moscow has also developed maritime drones with some similar design features.

While investigators have not established the vessel’s point of origin, Greek naval experts told ERT that the features of the washed-ashore craft resemble Ukrainian Magura-type drones. Those Magura-type systems have been used as explosive, remotely piloted ramming vessels in multiple maritime operations, the report said.

Officials’ next steps include examination at the naval base on the Greek mainland. Investigators’ findings are expected to help clarify whether the vessel is connected to maritime drone tactics being used in the Black Sea or whether it originated elsewhere.

The case underscores how unmanned maritime systems linked to the war in Eastern Europe can surface far beyond their presumed operating areas, prompting fast-response inspections by coastal and naval authorities.