After a week of insisting it merely assisted a vessel in distress by bringing it to a safe harbor, Iran on Thursday admitted its Islamic Revolutionary Guard Corps (IRGC) – designated a foreign terrorist organization by the United States – seized a foreign oil tanker and took its crew prisoner.

Iranian state television broadcast video of the ship, which appeared to be a missing tanker based in the United Arab Emirates.

Iranian media did not initially identify the captive vessel or reveal the identities of the crew, saying only that the ship was impounded for “smuggling” after it was seized in the Strait of Hormuz near an island with an IRGC military base.

Subsequent reports included images of the ship’s name and registration number, which matched that of the UAE-based, Panamanian-flagged tanker MT Riah, which has been missing since Sunday and last reported its position near the very same island.

The IRGC released a statement quoted by Iran’s Tasnim news agency detailing the capture of the Riah during “operations to detect and fight organized smuggling” and denying reports that another foreign tanker has been seized:

The IRGC Navy’s patrol vessels confiscated the foreign tanker that was carrying one million liters of smuggled fuel in a surprise operation after making sure that the ship was smuggling fuel, it added. According to the statement, the foreign tanker was seized in southern parts of Larak, a small island in the Persian Gulf, after obtaining a judicial warrant. There were 12 foreign crew on board the tanker which has a capacity of 2 million liters of fuel, the statement noted, saying it had received smuggled fuel from the Iranian launches and was going to deliver the fuel to the foreign ships in more distant regions.

As recently as Wednesday, the Iranians denied seizing any ships in the Strait of Hormuz and said the IRGC merely assisted a ship in distress after it encountered a “technical glitch.”

Iran has been threatening to kidnap foreign ships in retaliation for the United Kingdom’s seizure of an Iranian tanker for violating European Union sanctions on Syria this month. The Iranians have also long accused foreign ships of smuggling oil subsidized by Tehran, as explained by The Drive on Thursday:

The IRGC alleges that small civilian ships, commonly known in the region as dhows, had brought fuel illicitly to the ship and that the crew intended to leave the region and conduct further ship-to-ship transfers to then offload its fuel for shipment on to unspecified destinations. It is possible that the tanker was actually involved in illicit activity, but Iran has yet to present any hard evidence of this. The Iranian government heavily subsidizes gasoline, in particular, which has created a significant incentive for individuals to buy it at low prices in Iran and then smuggle it elsewhere to then sell it at a profit. This has created an odd situation where Iran, which routinely experiences shortages of gasoline due to limited domestic refining capacity and international sanctions, has to further contend with smugglers shipping what is available out of the country.

The Drive noted ownership and staffing of the Riah is “murky” and could trace back to either the U.K. or UAE, which would explain why both of those governments have announced they are carefully investigating the incident.

“The tanker in question is neither owned nor operated by the UAE. It does not carry Emirati personnel and did not emit a distress call. We are monitoring the situation with our international partners,” a UAE official said of the missing Riah earlier this week.

“We’re seeking further information following reports of a tanker seized in the Gulf. We continue to urge the Iranian authorities to de-escalate the situation in the region. We are continuously monitoring the security situation there and are committed to maintaining freedom of navigation, in accordance with international law,” a British official said on Thursday.

Although British authorities have floated the idea of releasing the Iranian tanker impounded for violating Syria sanctions to relieve tensions in the Persian Gulf, the Supreme Court of Gibraltar ruled on Friday that the ship can be held for 30 more days. Officials from Gibraltar, a British colony, said they are continuing to “work constructively and positively with officials of the Islamic Republic of Iran” to arrange the tanker’s release.