Illustrative: The Liberian-flagged oil tanker Ice Energy transfers crude oil from the Iranian-flagged oil tanker Lana (former Pegas), off the shore of Karystos, on the Island of Evia, Greece, May 26, 2022. REUTERS/Costas Baltas

Iran seized a tanker with Iraqi crude destined for Turkey on Thursday in retaliation for the confiscation last year of the same vessel and its oil by the United States, Iranian state media reported, a move likely to stoke regional tensions.

The seizure of the Marshall Islands-flagged St Nikolas coincides with weeks of attacks by Yemen’s Iran-backed Houthi rebels targeting Red Sea shipping routes.

“After the theft of Iranian oil by the United States last year, St Nikolas tanker was seized by Iran’s Navy this morning with a judicial order … it is en route to Iranian ports,” the semi-official Fars news agency reported, citing a statement by the Navy.

The St Nikolas was seized by the United States last year in a sanctions enforcement operation when it sailed under a different name, Suez Rajan. Following the move, Iran warned the US that it would “not go unanswered.”

The St Nikolas was boarded by armed intruders as it sailed close to the Omani city of Sohar, according to British maritime security firm Ambrey, and its AIS tracking system was turned off as it headed in the direction of the Iranian port of Bandar-e-Jask.

The ship loaded 145,000 metric tons of oil in the Iraqi port of Basra and was heading to Aliaga in western Turkey via the Suez Canal, its operator Empire Navigation told Reuters, adding that it had lost contact with the vessel.

While Yemen’s Houthis have since October attacked commercial vessels in the Red Sea to show support for the Palestinian terrorist group Hamas in its fight against Israel, those incidents have been concentrated on the Bab al-Mandab Strait, to the southwest of the Arabian Peninsula.

Thursday’s incident is located closer to the Strait of Hormuz, between Oman and Iran.

The vessel is manned by a crew of 19 including 18 Filipino nationals and one Greek national, the operator said, adding it was chartered by Turkish oil refiner Tupras.

The United Kingdom Maritime Trade Operations (UKMTO) authority said earlier on Thursday it had received a report that a vessel located around 50 nautical miles east of Oman’s coast was boarded by four to five armed persons.

The armed intruders were reported to be wearing military-style black uniforms and black masks.

The UK authority, which provides maritime security information, said it was unable to make further contact with the vessel and authorities were still investigating the incident.

The United States Navy’s Fifth Fleet did not immediately respond to a request for comment or further information.

The Suez Rajan was carrying more than 980,000 barrels of Iranian crude oil last year when it was seized and the oil confiscated in the US sanctions enforcement operation.

The United States said at the time that Iran’s Islamic Revolutionary Guard Corps (IRGC), a US-designated terrorist organization, had been trying to send contraband Iranian oil to China, in violation of US sanctions.

The vessel was unable to unload the Iranian crude for nearly two and half months over fears of secondary sanctions on vessels used to unload it. It was renamed the St Nikolas after unloading the cargoes.