Britain’s United Nations mission sent a letter to the UN Security Council on Saturday asserting that a British-flagged tanker seized by Iran was in Omani territorial waters and the incident “constitutes illegal interference.”
“The ship was exercising the lawful right of transit passage in an international strait as provided for under international law,” read the letter, which was seen by Reuters. “International law requires that the right of transit passage shall not be impeded, and therefore the Iranian action constitutes illegal interference.”
The letter was also sent to UN Secretary-General Antonio Guterres.
“Current tensions are extremely concerning, and our priority is to de-escalate. We do not seek confrontation with Iran,” the letter read. “But it is unacceptable and highly escalatory to threaten shipping going about its legitimate business through internationally recognized transit corridors.”
The Islamic Revolutionary Guard Corps said it seized the Stena Impero Friday for breaking “international maritime rules” in the strait, a choke point for around a third of the world’s sea-borne oil.
British Foreign Secretary Jeremy Hunt warned of “serious consequences” for the move and is expected to announce a series of diplomatic and economic measures aimed at Iran, the Telegraph reported.
The measures could include moves to freeze assets, and London could also push for the EU and UN to reimpose sanctions lifted under the 2015 nuclear deal, according to the report.
Hunt said Britain’s response “will be considered but robust.”
The tanker was impounded off Bandar Abbas port for allegedly failing to respond to distress calls and turning off its transponder after colliding with a fishing vessel, authorities said.
Britain said Iran had seized two ships in the Gulf, but the British owner of the Liberian-flagged Mesdar said it had been released after being temporarily boarded by armed personnel.
That came hours after a court in Gibraltar said it would extend by 30 days the detention of an Iranian tanker, the Grace 1, seized by British authorities two weeks ago on allegations of breaching EU sanctions against Syria.
The Guards also said Thursday they had seized another “foreign tanker” and its crew days earlier for allegedly smuggling fuel, without giving further details.
Hunt said Iranian officials “see this as a tit-for-tat situation, following Grace1 being detained in Gibraltar. Nothing could be further from the truth.”
In comments on Twitter on Saturday, Iran’s Foreign Minister Mohammad Javad Zarif characterized the seizure of Iran’s tanker July 4 as “piracy.” Politician and former Guard commander Maj. Gen. Mohsen Rezai wrote that Iran was not seeking conflict, “but we are not going to come up short in reciprocating.”
The spokesman for Iran’s Guardian Council, Abbas Ali Kadkhodaei, was also quoted in the semi-official Fars news agency describing Friday’s seizure as a legal “reciprocal action.” The council rarely comments on state matters, but when it does it is seen as a reflection of the supreme leader Ayatollah Ali Khamenei’s views. The council works closely with Khamenei, who has final say on all state matters.
Tensions in the Gulf have soared since May, with US President Donald Trump calling off airstrikes against Iran at the last minute in June after the Islamic Republic downed a US drone.
Washington has also blamed Iran for multiple attacks on tankers in the Gulf.
Trump said Friday’s incident “only goes to show what I’m saying about Iran: trouble. Nothing but trouble.”
The escalation comes more than a year after Washington unilaterally withdrew from the 2015 Iran nuclear agreement and began ratcheting up sanctions against Tehran.
Earlier this month, Iran exceeded the deal’s caps on uranium enrichment, aiming to pressure the remaining parties to make good on promises to help prop up its economy.
Tehran has repeatedly threatened to close the Strait of Hormuz if attacked.