Super tanker Grace I in Gibraltar.

Trouble In The Gulf: Everything You Need To Know

Jeremy Hunt says Britain will release Iranian tanker Grace 1, as long as the cargo does not break EU sanctions.

Super tanker Grace I in Gibraltar.

Foreign Secretary Jeremy Hunt says Britain will release an Iranian oil tanker - seized by Royal Marines in Gibraltar - as long as the cargo does not break EU sanctions and end up in Syria.

Iran's response has been that they should be allowed to continue oil exports on their own terms.

Anglo-Iranian tension remains high after the shipping attacks in the Gulf and the intervention of HMS Montrose in another incident.

Police in Gibraltar released the crew of the supertanker Grace 1, which was detained on suspicion of breaching EU sanctions against Syria.

The captain, chief officer and two second officers were conditionally bailed without charge, according to authorities.

The captain and his deputy were arrested on Thursday, while the other crew were arrested on Friday "as a consequence of the ongoing investigation into the suspected breach of EU sanctions on Syria," police said in a statement.

Iran has accused the UK of playing a "dangerous game", and being "servants of America" while demanding the immediate release of the tanker.

One of two tankers damaged in the Gulf of Oman in June (Picture: IRIB News/DPA).
One of two tankers damaged in the Gulf of Oman in June (Picture: IRIB News/DPA).

The comments come after the Ministry of Defence (MOD) announced a Royal Navy warship drove off three Iranian boats in the Strait of Hormuz.

The MOD said the boats, believed to be from the Iranian Revolutionary Guard Corps, were trying to stop a British tanker. 

A UK Government spokesman said they were "concerned" by the incident and called on Iran to "de-escalate".

Iran denied the claims but did previously warn Britain of "consequences" for seizing Grace 1.

It comes at a particularly sensitive time as tensions continue to bubble between the US and Iran.

What has happened so far?

13 June: Two US oil tankers near the Strait of Hormuz were attacked in an assault that left one ablaze and adrift, with 44 sailors evacuated from both vessels. The US Navy rushed to assist, with American President Donald Trump blaming Iran for the incidents.

Iran denied involvement in the tanker attacks and accused America of promoting an "Iranophobic" campaign.

20 June: An American military drone worth $100 million (£78 million) was downed by Tehran, with Iran's president Hassan Rouhani claiming it had violated their airspace.

The move marked a new high in the rising tensions between the two countries, as Iran's naval commander warned his forces would not hesitate to down more US drones if they entered its airspace.

Mr Trump then pulled back from the brink of retaliatory military strikes on Iran after he was told 150 people could die. He has since signed an executive order targeting Iran's supreme leader Ali Khamenei and his associates with financial sanctions.

 The RQ-4 Global Hawk, believed to be the drone shot down, is a high altitude, long-endurance craft (Picture: US Air Force).
The RQ-4 Global Hawk, believed to be the drone shot down, is a high altitude, long-endurance craft (Picture: US Air Force).

4 July: Royal Marines from 42 Commando were involved in an operation to seize a supertanker off Gibraltar suspected of carrying oil destined for Bashar al-Assad's Syrian regime. They boarded the ship by descending on ropes from a Wildcat helicopter and by using rigid inflatable boats.

They worked alongside authorities in Gibraltar to detain the Iranian tanker Grace 1, which was believed to be heading to the Banyas refinery in breach of European Union sanctions. In response, Iran's revolutionary guard warned a British oil tanker could be seized in retaliation.

10 July: Royal Navy frigate HMS Montrose drove off three Iranian vessels which tried to stop the commercial ship British Heritage.

It is understood the tanker was making passage out of the Gulf through the Strait of Hormuz when the ship was approached by the Iranian vessels. HMS Montrose was nearby and proceeded to come in between.

Warnings were given but no shots were fired. The Iranian vessels then turned around and left.

11 July: Police in Gibraltar arrested the captain and chief officer of the supertanker Grace 1.

In a statement, the Royal Gibraltar Police said the arrests followed a "protracted" search of the vessel, during which documents and electronic devices were seized.

12 JulyIran said Britain is playing "a dangerous game" as the country demanded the immediate release of the oil tanker.

Police in Gibraltar arrested two more officers on the supertanker. The two second mates, both Indian nationals, were interviewed under caution.

The UK government announced it would send a second warship to the Gulf amid escalating tensions with Iran. HMS Duncan, a Type 45 destroyer, is joining HMS Montrose, which is due to go in for "pre-planned maintenance" while continuing its deployment.

13 July: Gibraltar announce the release of the Grace 1 crew, but detain the tanker.

UK Foreign Secretary Jeremy Hunt says Britain will release the Grace 1 tanker, as long as the cargo does not break EU sanctions and end up in Syria.

The Iranian tanker seized (Picture: MOD).
The Iranian tanker seized (Picture: MOD).

What is the situation as it stands?

Tensions between the US and Iran have ratcheted up several notches in recent weeks, with Washington dispatching warships and bombers around the Persian Gulf, and Tehran announcing it would break uranium stockpile and enrichment limits set by its nuclear deal with world powers.

These increased strains come a year after President Trump withdrew from Iran's 2015 nuclear accord with world powers and restored crippling sanctions. In turn, this prompted Iran to say it would not negotiate another deal with Washington.

Foreign Secretary Jeremy Hunt has previously said Britain is urging all sides in the dispute to "deescalate" in order to avoid a slide into armed conflict, but he also previously said the UK would consider joining the US in military action.

The Tory leadership hopeful has said recent events in the Gulf show the need for extra investment in the Royal Navy.

Why is the Strait so important?

Its size belies its importance as one of the most strategic waterways in the world, linking the Middle East's crude oil producers with key markets around the globe.

The Strait falls between the southern coast of Iran and the most northerly tip of Oman, a distance of around 20 miles at these pinch-points.

It has two shipping lanes, each around two miles wide. Between one-fifth and one-sixth of the world's oil moves through the strait - around 17 million barrels per day - a significant quantity of the valuable commodity.

Any impasse on oil leaving the Strait could have wide-ranging consequences - including soaring prices and disruption to world supplies.

Will British troops be sent to the region?

At the moment, no. There is already an undisclosed number of British service personnel in the Middle East, predominantly from the Royal Navy. There is a joint base at Duqm in Oman, with a Combined Maritime Forces base in Manama, Bahrain.

HMS Montrose has been in the region since April as part of a three-year deployment supporting counter-terror and anti-smuggling work. The Royal Navy has had a presence in the region for more than 30 years following the Iran-Iraq war in 1980 in what is known as Operation Kipion.

Ships from both the Royal Navy and Royal Fleet Auxiliary have been on patrol in the Gulf for 24 hours a day, seven days a week and 365 days a year, according to the Royal Navy.