Former Iranian Revolutionary Guards leader makes dubious call for 'British oil tankers' to be seized

The former head of Iran's Revolutionary Guards has called on Tehran to seize British oil tankers in revenge for Gibraltar's holding of an Iranian ship destined for Syria.

"If England does not release the Iranian oil tanker, the duty ... (of Iran) is to respond and seize one English oil tanker," Mohsen Rezaei said on Twitter.

Rezaei is a powerful figure in Iran, serving as a key adviser to Supreme Leader Ayatollah Ali Khamenei.

Rezaei also led the Guards during the so-called "Tanker War" in the 1980s, targeting shipping belonging to the US and Arab states in the Gulf region, which were supporting the rival Baghdad regime.

Although the threat is not official Iranian government policy, some are alarmed by the prospect of further escalations in the Gulf, weeks after the US came close to retaliating after Tehran shot down an American drone.

Others have said that the claim is dubious given that British tankers are unlikely to go near Iran.

"Iran threatening to seize a UK oil tanker in retaliation... only problem for them is: a) We barely import any Middle Eastern crude b) are there even any UK-flagged oil tankers left?" tweeted David Sheppard, Financial Times energy editor.

Iran has also broken through a limit on uranium production set during a nuclear deal with world powers.

Six vessels are suspected to have been attacked by Iran forces in the past two months, while the US has rushed troops to the Gulf region and enforced a punishing blockade on Tehran.

British Royal Marines aided Gibraltar authorities seizing an Iranian supertanker on Thursday, accusing it of breaking sanctions on Bashar al-Assad's regime by shipping oil to Iran.

Tehran has responded furiously to the seizure, summoning the British ambassador for a formal complaint about the incident.

Spanish authorities said the seizure came at the request of the US.

A Gibraltar official has said that all 28 crew members - mostly Indian, Pakistani and Ukrainian - remain on the vessel and that they are being interviewed as witnesses and not suspected criminals.

The supertanker can only be detained for 72 hours unless the Supreme Court of the British overseas territory extends the deadline while the probe is conducted, Gibraltar media reported.

Agencies contributed to this story.