IRAN has today branded the UK "economic terrorists" and taunted the Royal Navy with pictures of one of its seized oil tankers.
Tehran's foreign minister accused Britain of being an "accessory to the economic terrorism of the US" as tensions escalated.
The UK has warned of "serious consequences" after Iran last night sparked a new Gulf crisis by seizing two British oil tankers.
Last night Iran's Revolutionary Guard launched a gunboat and helicopter raid on the Stena Impero, which is registered in the UK, claiming it had turned off its tracker and ignored warnings.
Another vessel, the Mesdar, was also intercepted and forced towards Iranian territory in what appeared to be a co-ordinated strike.
A UK warship sped to help a British oil tanker that was seized by Iran but arrived ten minutes too late.
The HMS Montrose was dispatched while the Stena Impero was in Omani waters but the warship arrived after the tanker had entered the Strait of Hormuz.
A defence source told the Times the Iranians appeared to be taking a "very aggressive stance" and were viewed as having been "ready to engage" HMS Montrose.
UK must cease being an accessory to economic terrorism of the US
Iran's foreign minister Javad Zarif
It comes as dramatic photos from last week showed HMS Montrose intercepting Iranian patrol boats surrounding the UK-flagged tanker British Heritage.
And Javad Zarif, Iran's foreign minister, stepped up the war of words with Britain, tweeting: "Unlike the piracy in the Strait of Gibraltar, our action in the Persian Gulf is to uphold international maritime rules.
"As I said in NY, it is IRAN that guarantees the security of the Persian Gulf & the Strait of Hormuz.
"UK must cease being an accessory to #EconomicTerrorism of the US."
A senior Iranian diplomat has been summoned to the Foreign Office following the seizure of the tanker, while Mr Hunt hopes to speak to Mr Jarif on the phone later today.
It comes two weeks after Royal Marines seized Iran's Grace 1 tanker off Gibraltar - prompting Tehran to threaten "retaliation".
The ship appeared to be in violation of EU sanctions on exporting oil to Syria but Iran called it an act of piracy.
The Iran Students News Agency, partially funded by the country's government, has also taunted the UK today by releasing pictures of the Stena Impero docked in Bandar Abbas, southern Iran.
Foreign Secretary Jeremy Hunt, who attended an emergency Cobra meeting, said there would be "serious consequences" and pledged a robust response.
But he added: "We're not looking at military options, we're looking at a diplomatic way to resolve the situation, but we are very clear that it must be resolved."
Mr Hunt said the Stena Impero was surrounded by four vessels and a helicopter, and was heading into Iranian waters.
'SERIOUS CONSEQUENCES'
The second ship, the Mesdar, was surrounded by 10 speedboats, he said.
Taking to Twitter on Saturday Mr Hunt said: "Yesterday's action in Gulf shows worrying signs Iran may be choosing a dangerous path of illegal and destabilising behaviour after Gibraltar's LEGAL detention of oil bound for Syria.
"As I said yesterday our reaction will be considered but robust. We have been trying to find a way to resolve Grace1 issue but WILL ensure the safety of our shipping."
President Donald Trump last night called Iran "nothing but trouble", adding: "It goes to show I was right about Iran."
Yesterday the British-flagged Stena Impero, which was bounded for Saudi Arabia from the UAE, suddenly changed course and was diverted towards the island of Qeshm, where Iran's Revolutionary Guard has a large base.
ESCALATION OF TENSIONS
Iran claimed the ship had "failed to respect international maritime rules" by switching off its tracker and heading the wrong way in a shipping lane.
Iran's state-run IRNA news agency since claimed the country's seizure of British-flagged oil tanker was due to a collision with an Iranian fishing boat.
The report said the British tanker caused damage to the fishing boat, then did not respond to calls from the smaller craft.
Sweden's Stena Bulk, the owner of the Stena Impero, said the Revolutionary Guard - classed as a terror group by the US - used small craft and a helicopter.
Erik Hanell, president and chief executive of Stena Bulk, said: "There are 23 seafarers onboard of Indian, Russian, Latvian and Filipino nationality.
"There have been no reported injuries and the safety and welfare of our crew remains our primary focus.
"We are in close contact with both the UK and Swedish government authorities to resolve this situation and we are liaising closely with our seafarers' families."
The Liberian-flagged by British-owned Mesdar was also diverted towards the mainland about 40 minutes later.
It was said to have been stormed by gunmen but later released.
Neither of the two ships had any British crew on board.
Housing Secretary James Brokenshire said the seizure of the tanker was "completely intolerable" and said the Government was seeking to establish diplomatic connections with Tehran.
He told Today: "The actions of the Iranians is completely unacceptable. It is so important that we maintain this free navigation through the Gulf and to seize a vessel in this way is just completely intolerable."
UK vessels have been advised to "stay out of the area" of the Strait of Hormuz for an "interim period", a government spokesman said.
TIMELINE OF THE IRAN CRISIS
June 13: Two US oil tankers near the Strait of Hormuz were attacked in an assault that left one ablaze and adrift, with 44 sailors evacuated.
July 4: Royal Marines off the coast of Gibraltar seize the supertanker Grace 1 suspected of carrying Iranian oil to Syria.
July 10: HMS Montrose trains its guns on Iran gunboats trying to hijack a British tanker, the BP-owned Heritage.
July 16: Iran's Ayatollah Khamenei called the seizure of the Grace 1 tanker "piracy" and vowed to retaliate, but Gibraltar is still holding it.
July 17: Iran seized a Panama-flagged oil tanker from the United Arab Emirates as it travelled through the Strait of Hormuz.
July 18: President Donald Trump reveals the US Navy shot down an Iranian drone in the Strait of Hormuz after warnings were ignored.
July 19: Two British oil tankers are boarded by Iran’s Revolutionary Guard in the Strait. One, the Stena Impero, is 'confiscated' with 23 crew on board.
The incident follows on from recent heightened tensions in the Gulf involving Iran, the US and UK.
Last week, the Royal Navy warship frigate HMS Montrose drove off three Iranian vessels which tried to stop the commercial ship British Heritage as it sailed through the Strait of Hormuz.
Fears were raised the Iranian authorities were trying to seize a UK ship in retaliation for the detention of the Grace 1 tanker.
The Iranian ship was detained off the coast of Gibraltar on July 4 after it was suspected of violating EU sanctions by carrying a cargo of crude oil to Syria.
The ship's captain, chief officer and two second officers were arrested and bailed and an investigation is ongoing.
Iran's supreme leader Ayatollah Ali Khamenei called the tanker's seizure an act of "piracy" on Tuesday and warned the UK to expect a response.
Mr Hunt offered to help release Grace 1 if Iran guaranteed it would not breach sanctions imposed on Bashar Assad's regime.
MOST READ IN WORLD NEWS
European allies to the US have been urged to take a tougher stance on Iran after Mr Trump withdrew from a nuclear deal with Tehran.
On Thursday, Mr Trump said a US warship shot down an Iranian drone in the Strait of Hormuz - something denied by Iranian military officials.
Last month, Mr Trump said he had made a last-minute decision to call off air strikes in retaliation for the shooting down by Iran of an unmanned US drone.
The crisis has followed Mr Trump's decision to withdraw the US from the 2015 nuclear deal that Iran signed with world powers.
We pay for your stories! Do you have a story for The Sun Online news team? Email us at [email protected] or call 0207 782 4368. You can WhatsApp us on 07810 791 502. We pay for videos too. Click here to upload yours.