The owner of Kokuka Courageous said its sailors saw "flying objects" before the attack. Blaming Iran for the incident, US military says video it released shows Revolutionary Guards removing an unexploded limpet mine from the vessel.
The US military released a video on Friday it said showed Iran's Revolutionary Guard removing an unexploded limpet mine from one of the oil tankers targeted near the strategic Strait of Hormuz, suggesting Tehran wanted to hide evidence of its alleged involvement.
Iran denied any role in Thursday’s apparent attacks, which have again roiled the Persian Gulf amid heightened tensions between Tehran and Washington over the unraveling nuclear deal with world powers.
Four other oil tankers off the nearby Emirati port city of Fujairah suffered similar attacks in recent weeks, and Iranian-allied rebels from Yemen have struck US ally Saudi Arabia with drones and missiles.
President Donald Trump withdrew America last year from the 2015 nuclear deal that Iran reached with world powers and recently imposed a series of sanctions now squeezing its beleaguered economy and cutting deeply into its oil exports.
While Iran maintains it has nothing to do with the recent attacks, its leaders repeatedly have threatened to close the vital Strait of Hormuz, through which 20 percent of the world’s oil flows.
Iran accused Washington of waging an "Iranophobic campaign" against it, while Trump countered that the country was "a nation of terror."
"Iran did do it," he said of the attack, in remarks on Friday morning to "Fox & Friends."
However, Iranian President Hassan Rouhani said the US poses a "serious threat to global and regional stability."
Rouhani said Washington has violated international law by using its economic and military resources against the world.
TRT World's Natasha Hussain has more on the story.
The black-and-white US video of the Iranians alongside the Japanese-owned tanker Kokuka Courageous came after its crew abandoned ship after seeing the undetonated explosive on its hull, said Capt. Bill Urban, a spokesman for the US military's Central Command. It separately shared photos of the vessel, which showed what appeared to be a conical limpet mine against its side.
In the video, the boat from Iran’s paramilitary Revolutionary Guard pulls alongside Kokuka Courageous at 4:10 p.m. Thursday. The Iranians reach up and grab along where the limpet mine could be seen in the photo. They then sail away.
Limpet mines, which are magnetic and attach to a ship’s hull, are designed to disable a vessel without sinking it.
Unidentified Flying Objects
The owner of the Kokuka Courageous said in Tokyo sailors saw "flying objects" before the attack, suggesting it wasn't damaged by mines.
Company president Yutaka Katada offered no evidence for his claim, which contradicts the US military account.
Katada also said crew members saw an Iranian naval ship nearby, but did not specify whether this was before or after the attacks.
The suspected attacks occurred at dawn Thursday about 40 kilometres (25 miles) off the southern coast of Iran.
The Front Altair, loaded with the flammable hydrocarbon mixture naphtha from the United Arab Emirates, radioed for help as it caught fire. A short time later, the Kokuka Courageous, loaded with methanol from Saudi Arabia and Qatar, also called for help.
The US Navy sent a destroyer, the USS Bainbridge, to assist, said Cmdr.
Joshua Frey, a 5th Fleet spokesman. He described the ships as being hit in a "reported attack," without elaborating.
US blames Iran
Thursday's attack resembled the one in May which targeted four oil tankers off the nearby Emirati port of Fujairah.
US officials similarly accused Iran of targeting the ships with limpet mines, which are magnetic and attach to the hulls of a ship.
The mines disable, but don't sink a vessel.
US Secretary of State Mike Pompeo told journalists on Thursday that the US assessment of Iran's involvement was based in part on intelligence, as well as the expertise needed for the operation.
It was also based on recent incidents in the region, which the US also blamed on Iran, including the use of limpet mines in the Fujairah attack, he said.
He also tied Iran to a drone attack by Yemen's Iranian-backed Houthi rebels on a crucial Saudi oil pipeline around the same time.
"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," Pompeo said. He didn't elaborate and took no questions.
Iran denied being involved in the attacks last month and its foreign minister questioned the timing of Thursday's incidents, given that Japanese Prime Minister Shinzo Abe was meeting Supreme Leader Ayatollah Ali Khamenei in Tehran.
Pompeo noted that Abe had asked Iran to enter into talks with Washington but Tehran "rejected" the overture.
"The supreme leader's government then insulted Japan by attacking a Japanese-owned oil tanker just outside Iranian waters, threatening the lives of the entire crew, creating a maritime emergency," Pompeo added.
At the United Nations, the Security Council held closed consultations on the tanker incidents late Thursday at the request of the United States but took no action.
Strait of Hormuz security under Tehran - Iran
Iran said on Friday it was responsible for maintaining the security of the Strait of Hormuz in the Gulf, state radio reported, adding that blaming Tehran for attacks on two oil tankers in the Gulf of Oman was alarming.
"We are responsible for ensuring the security of the Strait and we have rescued the crew of those attacked tankers in the shortest possible time," Radio quoted foreign ministry spokesman Abbas Mousavi as saying.
"Obviously, accusing Iran of such a suspicious and unfortunate incident is the simplest and the most convenient way for (US Secretary of State Mike) Pompeo and other US officials. These accusations are alarming."
Almost a fifth of the world’s oil passes through the Strait - some 17.2 million barrels per day (bpd). Consumption was about 100 million bpd in 2017, data from analytics firm Vortexa showed.
Brent crude futures rose 0.6 percent to $61.69 per barrel in Asian trade on Friday, having gained 2.2 percent the previous day, though at one point they had surged as much as 4.5 percent in the wake of the attacks.
Iran's key regional rival Saudi Arabia said that Riyadh was committed to providing reliable oil supplies to global markets.
Iran's nuclear option
Tensions have escalated in the Mideast as Iran appears poised to break the 2015 nuclear deal with world powers, an accord that President Donald Trump repudiated last year.
In the deal, Tehran agreed to limit its enrichment of uranium in exchange for the lifting of crippling sanctions. Now, Iran is threatening to resume enriching uranium closer to weapons-grade levels if European nations don't offer it new terms to the deal by July 7.
Already, Iran says it quadrupled its production of low-enriched uranium. Meanwhile, US sanctions have cut off opportunities for Iran to trade its excess uranium and heavy water abroad, putting Tehran on course to violate terms of the nuclear deal regardless.