A UK worker was one of two crew members killed in an attack on an oil tanker linked to an Israeli billionaire in the Arabian Sea on Thursday, according to the firm managing the vessel.

The UK Government later confirmed that a British national “has died following an incident on a tanker off the coast of Oman”.

The deaths mark the first fatalities after years of assaults targeting shipping the region.

No-one immediately claimed responsibility for the Thursday night raid on the Liberian-flagged tanker Mercer Street.

But a US official said it appeared a so-called “suicide drone” was used in the attack, raising the possibility that a government or a militia group was behind the incident.

The US navy rushed to the scene following the attack and was escorting the tanker to a safe harbour, a London-based ship management company said on Friday.

The Mercer Street
The Mercer Street (Johan Victor via AP)

The assault represents the worst-known maritime violence so far in regional attacks on shipping since 2019.

The US, Israel and others have blamed the attacks on Iran amid the unravelling of Tehran’s nuclear deal with world powers.

Iran now already appears poised to take an even tougher approach with the West as the country prepares to inaugurate a hard-line protege of Supreme Leader Ayatollah Ali Khamenei as president next week.

The attack on Thursday targeted the tanker just north-east of the Omani island of Masirah, more than 300km (185 miles) south-east of Oman’s capital Muscat.

London-based Zodiac Maritime, part of Israeli billionaire Eyal Ofer’s Zodiac Group, said two crew members – one from the UK and the other from Romania – were killed in the attack.

It did not name the pair, nor did it describe what happened in the assault. It said it believed no other crew members on board were harmed.

“At the time of the incident, the vessel was in the northern Indian Ocean, travelling from Dar es Salaam to Fujairah with no cargo onboard,” the statement from Zodiac Maritime said, naming ports in Tanzania and the United Arab Emirates respectively.

Satellite tracking data from MarineTraffic.com showed the vessel had been close to where British officials said the attack occurred. But the last signal the ship sent came early on Friday morning.

Former US president Donald Trump
Former US president Donald Trump unilaterally withdrew America from the nuclear deal with Iran in 2018 (Niall Carson/PA)

Zodiac Maritime described the Mercer Street’s owners as Japanese, without naming them.

Shipping authority Lloyd’s List identified the vessel’s ultimate owner as Taihei Kaiun Co, which belongs to the Tokyo-based Nippon Yusen Group.

Zodiac Maritime later said the tanker was sailing under the control of her crew “to a safe location with a US naval escort”. The US navy’s 5th Fleet, which patrols the Middle East, did not respond to a request for comment.

Meanwhile, United Kingdom Maritime Trade Operations said an investigation was under way into the attack and that coalition forces were taking part.

A US official said the attack appeared to have been carried out by a “one-way” drone and other drones took part. The official said it was not immediately known who had launched the attack.

An Israeli official blamed Iran for the attack and confirmed other public details of the incident. Israel considers Iran to be its biggest threat, citing Tehran’s hostile rhetoric, support for anti-Israeli militant groups and growing influence in the region.

The remarks came after an earlier report from private maritime intelligence firm Dryad Global referred to a drone sighting involving the vessel prior to the attack.

Iran and Yemen’s Tehran-backed Houthi rebels have employed “suicide” drones in the past. These are unmanned aircraft loaded with explosives that detonate on impact with a target.

British maritime security firm Ambrey said the attack on Mercer Street had killed one of its team members, along with a member of the tanker’s crew.

The intelligence firm said it was working with authorities and offering support to the victim’s family “at this incredibly sad time”.

Omani officials did not respond to requests for comment. The sultanate sits on the eastern edge of the Arabian Peninsula and is along vital shipping routes for cargo and energy moving through the Strait of Hormuz, the narrow mouth of the Persian Gulf.

Antony Blinken
The attack came the night after US Secretary of State Antony Blinken warned Iran that talks over the nuclear deal ‘cannot go on indefinitely’ (Chris J Ratcliffe/PA)

Israeli did not publicly acknowledge the attack.

Other Israeli-linked ships have been targeted in recent months amid a shadow war with Iran, with Israeli officials blaming the Islamic Republic for the assaults.

Israel meanwhile has been suspected in a series of major attacks targeting Iran’s nuclear programme. Iran also saw its largest warship recently sink under mysterious circumstances in the nearby Gulf of Oman.

Thursday’s attack comes amid heightened tensions over Iran’s tattered nuclear deal and as negotiations over restoring the accord have stalled in Vienna.

The series of ship attacks suspected to have been carried out by Iran began a year after former US president Donald Trump unilaterally withdrew America from the accord in 2018.

Iranian media quoted foreign press reports on Thursday’s attack but did not offer anything more.

The attack came the night after US Secretary of State Antony Blinken, speaking from Kuwait, warned Iran that talks in Vienna over the nuclear deal “cannot go on indefinitely”.

This is the second time this month a ship tied to Mr Ofer has reportedly been targeted.

In early July, the Liberian-flagged container vessel CSAV Tyndall, once tied to Zodiac Maritime, suffered an unexplained explosion on board while in the northern Indian Ocean, according to the US Maritime Administration.