Dubai - Iran has seized another foreign tanker in the Gulf, Iranian state media said on Sunday.

A Revolutionary Guard Corps commander was quoted as saying its naval forces had “seized a foreign tanker in the Persian Gulf that was smuggling fuel for some Arab countries”. It said the tanker was carrying 700,000l of fuel, adding that seven sailors had been detained.

The reported incident comes amid high tension after the US tightened sanctions on Iran’s oil sector. The sanctions were reimposed after Washington’s unilateral withdrawal from a landmark 2015 nuclear deal.

Iran has previously accused ships of smuggling fuel. On 13 July the Iranian coastguard detained the Panama-flagged MT Riah.

The Revolutionary Guards’ Sepah News site said at the time that the ship was seized during naval patrols aimed at “discovering and confronting organised smuggling”.

Also last month, Iran seized British-flagged tanker the Stena Impero in the Strait of Hormuz, saying it had collided with a fishing vessel.

The US has blamed Iran for two separate attacks using explosives which damaged oil tankers in the Gulf of Oman in May and June - an allegation Tehran has denied.

Fars news agency reported that the operation to seize the ship was carried out last Wednesday near the Gulf island of Farsi. The tanker was taken to Bushehr and its fuel handed over to the authorities, the agency added.

It is not yet clear what flag this ship was flying under nor the nationalities of the seven crew. The ship does not seem to have been noted as missing.

Britain has mooted the idea of a European-led maritime force in the Strait of Hormuz, a proposal rejected by Iran as an infringement of its sovereignty.

US Secretary of State Mike Pompeo said on Sunday that the US is still talking with allies about its proposed “Operation Sentinel.”

Speaking at a meeting between US and Australian leaders, US Defence Secretary Mark Esper said he has already gotten a good response from allies and some announcements could be expected soon. And Pompeo told reporters that a lot of conversations are taking place.

Marine Gen Joseph Dunford, the chairman of the US Joint Chiefs of Staff, has said the Pentagon has developed a specific plan for Operation Sentinel, which would see the US military’s main role as providing “maritime domain awareness” – intelligence and surveillance information - to the ships of coalition partners.

Any escorting of commercial ships would be done by military ships sailing under the flag of the commercial vessel, he said.

After the US last year pulled out of the Iranian nuclear deal, the Trump administration also increased sanctions against Iran, and this could help explain what we are now seeing in the increasingly tense Strait of Hormuz, said Holly Dagres, Iran expert and non-resident fellow at the Atlantic Council.

“Iran believes the United States declared economic warfare when it announced as part of its ‘maximum pressure’ policy to bring Iranian oil exports down to zero,” Ms Dagres told The Independent.

“Tehran threatened to retaliate by closing the Strait of Hormuz – though it didn’t explain how. What we are seeing in recent weeks is Iran begin to make good on that threat, by making shipping more precarious through the Strait.”

“Whether this latest oil tanker was in fact smuggling oil or not, the United States will point to this latest incident as more incentive for allies to join ‘Operation Sentinel’,” she added.

“Having that been said, if this operation goes into full force, it will likely lead down a path of direct conflict in the near future - as long as Tehran continues to feel the impact of sanctions.”

The cargo of the unnamed ship, which was seized on Wednesday, has been handed over to the National Oil Distribution Company’s branch in Bushehr, Brig-Gen Ramezan Zirahi (Ramazan Zirahi) said, the semi-official ISNA news agency reported on Sunday.

“Naval units of IRGC’s Navy 2nd Zone are performing duty as per routine and with all-out intelligence domination to protect the national interests with full force and will not hesitate for a moment in performing this crucial task,” Zirahi said.