An Iranian general on Friday warned the country could seize a British ship in retaliation after Royal Marines boarded and impounded a tanker carrying Iranian oil.
"If Britain does not release the Iranian oil tanker, it is the authorities’ duty to seize a British oil tanker," Mohsen Rezai, a Major General in the Revolutionary Guards Corps and head of the country’s influential Expediency Council, which advises the Supreme Leader Ayatollah Ali Khamenei.
"Islamic Iran in its 40-year history has never initiated hostilities in any battles but has also never hesitated in responding to bullies," Maj Gen Rezai added.
Iran’s foreign ministry accused Britain of “piracy” and summoned the British ambassador in Tehran after Royal Marines helped customs officers impound the Grace 1 supertanker near Gibraltar on Thursday.
The British and Gibraltarian governments said the ship, owned by a Dubai-based company with ties to Tehran, was believed to be carrying two million barrels of crude oil to Syria, in breach of European Union sanctions against Bashar Assad’s regime.
The government of Gibraltar said on Friday that the crew of Indian, Pakistani, and Ukrainian are being interviewed as witnesses in order to establish the nature of the cargo and its destination.
On Friday Gibraltar’s Supreme Court granted an order to the territory’s authorities allowing them to hold the tanker for another fortnight. The Gibraltar government said the ruling had been made on the basis that there were "reasonable grounds" to believe the ship was breaking EU sanctions by transporting oil to Syria.
The incident has damaged attempts to tried to remain neutral in a brewing confrontation between the United States and Iran.
The US on Friday requested an emergency meeting of the UN’s nuclear watchdog to discuss Iran, days after Tehran breached a uranium enrichment limit set in a 2015 nuclear deal with world powers.
Britain publicly defends Iran’s right to sell oil under the 2015 nuclear deal and opposes US attempts to blockade its exports, and diplomats in London have insisted that the seizure was connected only with European Union sanctions against Syria, not US sanctions against Iran.
France said on Thursday that a special trade mechanism, Instex, aiming at making it possible trade between EU members and Iran to continue in the face of US sanctions, would complete a first, limited transaction in the coming days.
But the foreign minister of Spain, which disputes British ownership of Gibraltar, said the UK acted on a request by the United States.
An Iranian foreign ministry spokesman said on Thursday the incident showed Britain was following “the hostile policies of the United States, which is unacceptable to Iran".
The government of Gibraltar said it acted entirely independently and denied seizing the tanker at the request of the United States or any other country.
"There has been no political request at any time from any Government that the Gibraltar Government should act or not act, on one basis or another," it said in a statement on Friday.
The US and Britain have blamed Iran for a series of sabotage attacks against tankers near the Strait of Hormuz in May and June, and General Rezai’s threat will be taken seriously by maritime security operators.
But following through on the threat to seize a British ship would be complicated by the often opaque structure of modern shipping.
“What is a British vessel? It is not so straightforward. You could be company registered in Liberia and be flagged in Panama but have a British owner. Or you could be a UK flagged vessel with the company registered in France with a German owner,” said Michelle Bockmann, a commodities shipping analyst and editor at Lloyd’s List.
“On the balance of probabilities it is the kind of threat being made in line with previous threats to close the strait of Hormuz. There is always bellicose rhetoric, but let’s hope it is unlikely to materialise.”
At least one British-flagged tanker, a super-tanker called the Pacific Voyager, passed through the strait of Hormuz en route to the Saudi port of Ras Tanura on Friday. It is Japanese-owned, operated by a Singaporean company, and hired by a subsidiary of a South Korean firm.
Maersk, the Danish shipping giant, on Thursday announced it would levy a war risk surcharge on cargos transiting the Persian Gulf.