The vessels, each carrying about two million barrels of crude oil, used an unauthorised route, the IRGC says.

Iran’s Islamic Revolutionary Guard Corps (IRGC) has said two oil tankers, each carrying about two million barrels of crude oil, caught fire after hitting naval mines in the Strait of Hormuz.

The first tanker hit a mine, triggering an explosion and a “fierce fire”, the IRGC said on Saturday, while the second tanker hit a mine that engulfed it “in a massive blaze”, Iran’s official IRNA news agency reported.

Information about the ships’ names or the origin of their cargo was not immediately available.

IRNA said the vessels had switched off their positioning and radar systems and tried to use a route not authorised by Iran.

The IRGC also claimed that while one tanker tried to cross the waterway “with US support”, the second vessel was left immobilised.

Iran seized control of the Strait of Hormuz after the US-Israeli war on the country began in late February. Tehran has since demanded that all ships seek its authorisation before transiting. About one-fifth of global oil consumption transited the waterway before the war.

This week, IRGC naval commander Rear Admiral Ali Azmaei warned that any vessel that deactivated its navigation systems would be considered “hostile”.

The United States has imposed its own naval counter-blockade on Iranian oil exports.

Iran’s army earlier said that two tankers caught fire on Thursday and Friday in Tehran’s “prohibited zone” in the Gulf of Oman.

Maritime monitors also reported two tankers struck in Gulf waters off Saudi Arabia on Friday.

Last Sunday, six vessels were attacked in or near the Strait of Hormuz, the most in a single day since the war began, according to security firm Vanguard, the International Maritime Organization and the UK maritime agency UKMTO.

Attacks around the waterway have surged over the past two weeks, with Iran saying it is stepping up strikes in response to the US blockade of its ports and tougher sanctions imposed last month.

Nearly 20.8 million barrels of oil passed through on October 8, but only 2.9 million on October 11, according to Kpler data.

The disruption has pushed up global energy prices and inflation.

US President Donald Trump has explicitly ruled out using a nuclear weapon against Iran. “I wouldn’t use nuclear,” he told the Newsmax news site in an interview on Thursday.

Trump said that he was also not considering putting troops on the ground in Iran. “No, I don’t see that, I don’t see it,” he said, adding he believes a deal to end the war will be reached after the November 3 US midterm elections.