Muscat: US Secretary of State Mike Pompeo has said that Iran is responsible for attacks on two tankers in the Gulf of Oman.

He said the United States government is drawing this conclusion based on “on intelligence, the weapons used, the level of expertise needed to execute the operation” — but he did not offer any concrete evidence to support the claim.

National Security Adviser John Bolton earlier also spoke out to put responsibility on Iran, but also did not offer evidence.

Iranian Foreign Minister Mohammad Javad Zarif had noted that one of the ships is Japanese owned and that the attack took place as Japanese Prime Minister Shinzo Abe was visiting Iran. He called the attack “suspicious” in a tweet.

“Reported attacks on Japan-related tankers occurred while PM [Shinzo Abe] was meeting with Ayatollah [Khamenei] for extensive and friendly talks. Suspicious doesn’t begin to describe what likely transpired this morning,” Zarif tweeted.

Meanwhile, Russia has cautioned against “hasty statements” over the attack, with a spokesperson for the Kremlin saying it was premature to draw conclusions about the cause of the incident.

Two oil tankers were hit in a suspected attack in the Gulf of Oman early on Thursday, causing oil prices to surge and raising the already heightened tensions in the Middle East.

The tankers were struck in the same area where the US accused Iran of using naval mines to sabotage four other oil ships in an attack last month.

One of the tankers is carrying “Japan-related” cargo, and Iran’s Supreme Leader Ayatollah Ali Khameneni is meeting with Japanese Prime Minister Shinzo Abe in Tehran.

As the news filtered from the Gulf, Iran’s Foreign Minister tweeted in English that, “suspicious doesn’t begin to describe what likely transpired this morning”.

One of the ships, the Norwegian-owned Front Altair, was “suspected of being hit by a torpedo”, according to Taiwan’s state-owned petrol company. The ship was on fire, its owners said.

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.

The company said the ship was safely afloat.  Oil prices jumped by 4 per cent in response to reports of the attack.

The UK Maritime Trade Operations (UKTMO), a unit of the Royal Navy, said it was aware of an incident in the area but gave no further details. “UK and its partners are currently investigating,” UKTMO said.

The alleged attack happened outside the Strait of Hormuz, the strategic waterway between Iran and Oman through which around 20 per cent of all the world’s oil is transported.

The latest incident comes amid weeks of heightened tensions between the US and Iran.