A US-flagged oil tanker was approached by armed Iranian boats while sailing through the Strait of Hormuz on Tuesday, according to maritime security firms and Western military authorities.

The incident took place in one of the world’s most important shipping routes amid heightened tensions between the United States and Iran.

Maritime security firm Vanguard Tech reported that the tanker, Stena Imperative, was transiting about 16 nautical miles north of Oman when several small armed boats linked to Iran’s Islamic Revolutionary Guards Corps moved towards it.

The firm said the boats contacted the vessel by radio and ordered the crew to stop the engines and prepare to be boarded. The tanker did not comply and instead continued on its planned route.

Vanguard Tech stated that the Stena Imperative remained outside Iranian territorial waters throughout the incident.

The firm added that the vessel was later escorted by a US Navy warship to ensure its safe passage through the area.

US Central Command said that Iranian boats, supported by an Iranian Mohajer drone, approached the tanker at high speed and threatened to seize it.

According to the command, the US guided-missile destroyer USS McFaul responded to the situation and escorted the tanker, with additional defensive air support provided by the US Air Force.

Vessel tracking data from MarineTraffic showed that the tanker stayed within Oman’s maritime economic zone while passing through the strait.

The Stena Imperative continued its voyage and was still on course for Bahrain, with an expected arrival at the port of Sitrah on 5 February.

Earlier, the United Kingdom Maritime Trade Operations (UKMTO) reported an incident in the same area, stating that a vessel had been hailed on VHF radio by several small armed boats within the inbound traffic separation scheme of the Strait of Hormuz.

UKMTO said the vessel ignored the request to stop and continued on its route, adding that authorities were investigating the incident and advising ships in the area to transit with caution.

Iran’s semi-official Fars News Agency cited unnamed officials who claimed that a vessel had entered Iranian territorial waters without the necessary legal documents.

According to the report, Iranian naval forces warned the vessel, which then left the area without any further incident.

The Stena Imperative is part of the US Tanker Security Program, a fleet intended to ensure the US Department of Defense has continued access to American-flagged fuel tankers.

The Strait of Hormuz connects the Persian Gulf with the Gulf of Oman and the Arabian Sea and handles around a quarter of the world’s seaborne oil trade.

Iran has previously harassed or seized vessels near the strait, with several tankers detained in recent years. Last week, Greece advised its tanker fleet to exercise caution while transiting the waterway.

In a separate incident on the same day, US Central Command confirmed that US forces shot down an Iranian Shahed-139 drone after it flew towards the US aircraft carrier USS Abraham Lincoln in the Arabian Sea.

References: Bloomberg, Reuters