Iran’s Foreign Ministry Spokesperson Abbas Mouvi said they had summoned the British ambassador in Tehran over the “illegal seizure” of the oil tanker.
British Royal Marines seized an oil tanker in Gibraltar Thursday over bringing oil to Syria in violation of sanctions put by the European Union on the Arab nation.
The Grace 1 tanker was impounded in the British territory at the mouth of the Mediterranean Sea after sailing around Africa from the Middle East.
Refinitiv Eikon mapping system suggests it had been loaded with “Iranian oil” off the coast of Iran, although its documents say the oil is from neighboring Iraq.
In a statement, the Gibraltar government said it had reasonable grounds to believe that the Grace 1 was carrying its shipment of crude oil to the Baniyas refinery in Syria.
"That refinery is the property of an entity that is subject to European Union sanctions against Syria," Gibraltar Chief Minister Fabian Picardo said. "With my consent, our port and law enforcement agencies sought the assistance of the Royal Marines in carrying out this operation."
Iran’s Foreign Ministry Spokesperson Abbas Mousavi told state media that the country had summoned the British ambassador in Tehran over the “illegal seizure” of the oil tanker.
Spain, which challenges British ownership of Gibraltar, said the action was prompted by a U.S. request to Britain and appeared to have taken place in Spanish waters.
Gibraltar was occupied by British troops during the Spanish Succession War in 1704. The British Crown turned this territory into its colony in 1713.
The United Nations included Gibraltar in the list of "territories pending decolonization" in 1963 and has recommended since 1965 that the sovereignty dispute must be solved through bilateral negotiations between the United Kingdom and Spain.
While Europe has banned oil shipments to Syria since 2011, it had never seized a tanker at sea.
"This is the first time that the EU has done something so public and so aggressive. I imagine it was also coordinated in some manner with the U.S. given that NATO member forces have been involved," said Matthew Oresman, a partner with law firm Pillsbury Winthrop Shaw Pittman who advises firms on sanctions.
The 300,000-tonne, Panamanian-flagged tanker is registered as being managed by Singapore-based IShips Management Pte Ltd. It was documented as loading fuel oil in the Iraqi port of Basra in December, though Basra did not list it as being in port and its tracking system was switched off. The tanker then reappeared on tracking maps near Iran's port of Bandar Assalyeh, fully loaded.
According to shipping data, Grace 1 sailed to the Mediterranean around the southern tip of Africa, instead of via Egypt's Suez Canal. The ship may have made the journey around Africa to avoid the Suez Canal, where such a large super-tanker would have had to unload its oil and refill after passing through, exposing its cargo to potential seizure.
This could escalate confrontation between Iran and the West, especially after the U.S. pulled out the 2015 Nuclear deal despite objections from EU powers and put sanctions on Iran.
This week Iran breached the nuclear deal and produced uranium beyond the allowed amount in a challenge to U.S. President Donald Trump’s sanctions, and to place pressure on European powers to enforce the nuclear deal.