Greece has impounded a Russian oil tanker off the island of Evia, the Greek coastguard said on Tuesday. A US advocacy group said it was carrying Iranian oil.

A Greek shipping ministry official said the 115,500-tonne Russian-flagged Pegas, with 19 Russian crew members, had been seized under European Union sanctions imposed on Russia over the Ukraine crisis.

The vessel was seized near Karystos on Evia’s southern coast, just off the mainland near Athens. Earlier this month, the EU banned Russian-flagged vessels, with exemptions, from its ports.

The US advocacy group United Against Nuclear Iran (UANI), which supports US sanctions against Iran and monitors tanker traffic through satellite tracking, said the Pegas − renamed the Lana in March − had loaded 700,000 barrels of crude oil from Sirri island, Iran, on August 19, 2021. The tanker headed to Greece after trying unsuccessfully to unload the oil at a Turkish port, UANI said.

The Athens News Agency reported that before being seized, Pegas had a breakdown and was being pulled by tugs to Greece's Peloponnese peninsula, where its cargo was to be moved to another vessel, and that during this journey it was forced by rough seas to moor near Karystos, where it was seized by Greek port authorities.

Associated Press reported the seizure was Friday. Reuters cited witnesses Tuesday that the Peags was still moored at Karystos bay, and was told by the Greek coastguard that the tanker’s cargo had not been impounded.