A tanker transiting the Strait of Hormuz was temporarily disabled after a small boat attached two limpet mines to its hull, causing an engine-room fire, according to maritime security sources.

The incident occurred on October 29, around 25 nautical miles northeast of Khasab, Oman, the United Kingdom Maritime Trade Operations (UKMTO) said in an advisory.

Context: Strait of Hormuz Intelligence File · Strait of Hormuz shipping guide · Strait of Hormuz

UKMTO said the crew were safe, the fire had been extinguished and there had been no environmental impact. The agency did not identify the ship, but three maritime security sources assessed that the vessel was the Panama-flagged tanker Louise 1.

Operational context

The tanker was continuing to its next port of call after the incident, UKMTO said.

It was not immediately clear who carried out the attack. The incident took place amid repeated attacks on commercial vessels in and around the Strait of Hormuz since the outbreak of conflict between the United States and Iran in February.

Iran has targeted vessels that it says breached its restrictions on passage through the strategic waterway, as it seeks to exert control over the strait and increase pressure on Washington.

According to two maritime security sources, the attack on Louise 1 was the first known successful use of limpet mines in the area since the conflict began. It followed an attempted limpet-mine attack in September in which the devices did not detonate.

What it means for maritime operators

Greece-based maritime risk management group Marisks said the incident raised concerns about the ability of small craft to approach commercial vessels in the Strait of Hormuz, attach explosive devices and depart in congested shipping lanes.

Marisks said limpet mines had first been deployed in the region in 2017 and had subsequently been used against tankers in the Strait of Hormuz. It described the method as low-cost and technically simple, while warning that it can be effective against ships in transit.

The Louise 1 had previously been targeted in July by Ukrainian naval drones in the Black Sea, according to Ukraine's SBU security service. The SBU said at the time that the tanker had been involved in transporting Russian oil and was part of a so-called shadow fleet used to sustain Russian oil exports.

The vessel's Panama-based operator, Aquarius Maritime Ventures, could not immediately be reached for comment.