At sea, where the renewed conflict has again cut off energy supplies from the Gulf, US Marines boarded a tanker near the Strait of Hormuz.

Iranian media reported, citing Iran’s Revolutionary Guards, that two oil tankers exploded and caught fire after passing through a mined route south of the strait, but the US military labelled the report as false.

Armed men seized another vessel off Yemen, raising concern over security in the Middle East’s other big choke point for oil shipments at the mouth of the Red Sea. Iran’s state television quoted the Revolutionary Guards as saying that until US “aggression” comes to an end, it will not be possible to export chemical fertilisers or even a “single drop of oil and gas” from the region.

The Revolutionary Guards later said four “violating” vessels that attempted to pass through the strait in recent hours were stopped through a combined missile and drone operation.

Washington and Tehran have been testing the limits of escalation since their ceasefire agreement collapsed last week, raising the prospect of a return to all-out war.

After reports of the escalation on Friday, benchmark Brent crude oil prices climbed 3% and were on track for a third consecutive weekly gain, putting political pressure on US President Donald Trump ahead of November congressional elections.

Trump has threatened to launch broad-based air strikes on Iran’s infrastructure and has also declined to rule out a ground assault on Iran’s coast or islands. US officials have said attacks on southern Iran are designed in part to give Trump options. Such moves risk provoking Iran to hit the vital infrastructure of vulnerable Gulf states or having its allies in Yemen further disrupt global energy supplies by attacking shipping from the Red Sea.

Iranian media reported enemy strikes early on Saturday in coastal Hormozgan Province on the Iranian side of the Strait of Hormuz. State Television said three people were killed and eight wounded while two bridges and a road tunnel were damaged.

Mohsen Rezaei, an Adviser to Iran’s supreme leader, warned on Friday against US escalation or any attempt to seize Iranian territory.

“If US strikes continue for several more days, we will move into a phase of full-scale offensive operations,” Rezaei, a former Revolutionary Guards top commander, told state television. Iranian state media earlier said at least five bridges were struck in the south in US attacks early on Friday.

Seven people were reported killed in attacks on bridges in the southern port of Bandar Khamir, where the train station was also hit. An airport was reported to have been hit further east and away from the coast in Iranshahr, in a province bordering Pakistan.

Iran announced attacks on Gulf countries that host US airbases, including Bahrain, Qatar and Kuwait, in addition to a US vessel in the northern Indian Ocean. Authorities in Kuwait said one of the country’s power generation and water desalination stations had been hit in an Iranian attack, causing damage, a fire and the disruption of a large number of electricity generation units.

The Kuwaiti army later said it was responding to Iranian drone attacks. The Revolutionary Guards said it attacked a depot of US drones in Bahrain and destroyed Bahrain’s main artificial intelligence centre with ballistic missiles and drones.

—Reuters—