- US points finger of blame at Iran
- Oil prices surge after suspected tanker attack
- Two tankers reportedly damaged by explosions
- Iran: 'Suspicious doesn't begin to describe this morning'
- Almost 50 sailors rescued from tankers
- Analysis: How the Strait of Hormuz became the world's most important choke point
The US accused Iran of being behind attacks in the Persian Gulf on Thursday and said it would raise the issue at the United Nations after two oil tankers were seriously damaged in an attack.
The explosions, which left one of the oil tankers burning outside the strategic Strait of Hormuz waterway, marked the most serious incident since the White House warned in early May that Iran was plotting attacks in the region.
Mike Pompeo, the US Secretary of State, said: "Taken as a whole these unprovoked attacks present a clear threat to international peace and security, a blatant assault on the freedom of navigation and an unacceptable campaign of escalating tension by Iran".
During a press conference Mr Pompeo said the US assessment of Iran's responsibility was based on intelligence sources, the weapons used and the level of expertise needed to execute the operation, saying "no proxy group operating in the area has the resources and proficiency to act with such a high degree of sophistication".
All 44 crew members of the two oil tankers were safely evacuated. The 23 sailors aboard the Norwegian-owned Front Altair were taken to Iran while 21 more on the Japanese-owned Kokuka Courageous were rescued by a US warship. There did not appear to be any spillage of oil or chemicals.
Thursday’s attack came one month after Iranian forces allegedly used naval mines to blow holes in two oil tankers and two smaller ships off the Emirati port of Fujairah. The US publicly said Iran was behind the attack, and pointed to similarities with yesterday's attack, while Tehran denied responsibility.
Javad Zarif, the Iranian foreign minister, said “suspicious doesn’t begin to describe” the incident in Gulf of Oman. He previously suggested without evidence that Israel was staging the attacks to undermine Iran.
Responding to Mr Zarif's comments, Mr Pompeo said: " Foreign Minister Zarif may think this is funny but no one else in the world does."
The explosions at sea came hours before Shinzo Abe, Japan’s prime minister, met with Ayatollah Khamenei, the supreme leader of Iran, on a diplomatic mission intended to try to ease tensions between Iran and the US. But the Japanese leader’s efforts appeared to bear little fruit.
Ayatollah Khamenei refused to hear any messages from Donald Trump delivered by Mr Abe, the Iranian government said.
The ayatollah also said Iran was not seeking nuclear weapons but “America could not do anything” to stop Tehran if it did decide to pursue a nuclear course.
Both tankers were carrying “Japanese-related” cargo, according to Japan’s government.
It was not clear if that was a coincidence or if the targeting of the ships was done deliberately to coincide with Mr Abe’s visit to Tehran.
While Iran’s civilian government denies responsibility for any of the attacks, it is possible that the Revolutionary Guard, who answer directly to the supreme leader, are carrying out operations without the government’s knowledge or consent.
Iran tries to keep tensions between the two sides concealed but they spilled into the open early this year when Mr Zarif threatened to resign after he was left out of a key meeting while a senior Revolutionary Guard commander was invited.
The attacks capped six weeks of building tensions between Iran and the US during which time Mr Trump has ordered an aircraft carrier, a bomber taskforce and 1,500 additional troops to the Middle East.
Both the US and Iran say they are not looking for war but Britain and other countries have warned of the danger that the two sides could stumble into an unintended conflict.
Antonio Gutteres, the UN secretary general, condemned the attack and warned that the world cannot afford “a major confrontation in the Gulf region”.
Any fighting near the Strait of Hormuz, the waterway which transports 20 per cent of the world’s oil, would likely cause serious damage to global energy supplies.
Analysts said that Iran appeared to be lashing out in order to send a message in response to crippling US sanctions imposed by Mr Trump after he withdrew the US from the 2015 nuclear deal.
“I think Iran is showing that it has teeth,” said Charles Hollis, a former British diplomat in Tehran who is now managing director of the Falanx Assynt consultancy. “It’s a way of showing that if they are backed into a corner they are not without means of causing grief.”
Details of the attack remained sketchy but the crew of the Front Altair reported reported hearing three explosions. Aerial footage from Iranian state television showed a fire raging on the starboard side of the ship while the rear also appeared damaged and blackened.
The ship was “suspected of being hit by a torpedo”, according to Taiwan’s state-owned petrol company. The second tanker, Kokuka Courageous, was damaged in a "suspected attack" that breached the hull above the water line while on passage from Saudi Arabia to Singapore, according to Bernhard Schulte Ship management.
Oil prices rose more than 4 per cent in response to Thursday’s explosions, the strongest surge in five months. Prices later came down to around 2 per cent above their opening level and overall prices remain lower than they were a month ago.
“This is a fairly small increase given the uncertainty and the potential knock-on effects of attacks such as these,” said Cailin Birch, global economist at The Economist Intelligence Unit.
She said markets had to some extent already factored in instability in the Gulf after the hostilities of recent weeks. Iran has warned that it will begin enriching high-grade uranium, the kind that could be used for a nuclear weapon, in July unless Europe finds a way to get around US sanctions and prop up the Iranian oil and banking sectors.
Such a move would be a violation of the 2015 nuclear agreement and the EU has warned Iran not to take this step. Britain, France, and Germany have defied the US by building a financial vehicle designed to circumvent American sanctions and allow trade with Iran.
But so far there is little sign that businesses are prepared to risk getting caught in US sanctions by using vehicle, known as Instex. Heiko Mass, Germany’s foreign minister, visited Tehran earlier this week to urge the Iranians not to violate the nuclear agreement.
He said it was in Iran’s “political and strategic interest to maintain this agreement and the dialogue with Europe”. Iran accused the European states of failing to live up to their commitments.
Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.