Iran deploys drones, grenades and mines against Hormuz shipping

U.S. strikes Qeshm Island as maritime attacks expand

Regional officials, security firms and analysts said Iran has expanded an asymmetric campaign against commercial shipping in and around the Strait of Hormuz, including vessels that shuttle oil out of the Persian Gulf to waiting tankers. The campaign has used bomb-laden undersea drones, rocket-propelled grenades and limpet mines as oil flows through the Persian Gulf remain below prewar levels. The Wall Street Journal reported that U.S. forces struck Iran’s Qeshm Island on Monday as part of unannounced small-scale strikes in the waterway aimed at halting attacks on American assets and passing ships.

The Wall Street Journal said Iran’s guerrilla tactics were meant “to shore up the regime’s fast-eroding position in the conflict” and pressure the Trump administration in deadlocked negotiations. The newspaper characterized the Islamic Republic’s battle to block that escape route as a “shadow war” inside the wider U.S.-Iran conflict, with a direct impact on global energy prices as American forces struck back.

The attacks are designed to disrupt individual oil shipments and re-establish the “climate of fear” that gripped shippers at the start of the conflict, The Wall Street Journal reported. When Iran began to fire into the waterway, it “paralyzed shipbound trade in the region,” the newspaper said.

The disruption is showing in energy markets: benchmark Brent crude traded around $102 a barrel on Tuesday, up from just over $70 before the war, while the average U.S. gallon of gasoline cost about $4.15 as American voters cast ballots in the midterm elections.

Since late August, Iran has used underwater, bomb-carrying sea drones to attack several commercial vessels, regional officials said. Maritime experts said Iran has resumed limpet mines, a weapon it deployed in 2019. The U.S. Navy said Iran used limpet mines against ships off the United Arab Emirates in 2019 as tensions rose over President Trump’s withdrawal from the nuclear deal with Tehran.

On Friday, a small boat approached the port side of a tanker just north of Oman and attached two explosives to the hull above the waterline. The subsequent blasts caused a fire in the engine room and temporarily disabled the ship, the U.K. Maritime Trade Operations Center said.

October marked the highest monthly number of attacks in the strait since the war began, with more than 35 incidents logged by UKMTO, which is affiliated with the Royal Navy. At least five vessels have been struck so far in November, UKMTO said.

For weeks, the Islamic Revolutionary Guard Corps has claimed through Iranian state media that mines laid by its forces damaged commercial ships. Gulf officials said those assertions were designed to sow panic among shippers and doubt about the U.S. demining effort, with the ultimate aim of disrupting oil flow. The Wall Street Journal said Tehran’s lack of acknowledgment of the specific nature of the drone attacks was likely intended to suggest that mines still littered the strait.

The scope and location of the attacks have expanded as more oil has begun leaving the strait, extending beyond tankers to containerships, bulk carriers and gas carriers, including vessels anchored outside the strait elsewhere in the Persian Gulf. Iran has seen much of its navy sunk by U.S. forces during the war, likely making the use of civilian vessels more necessary, the report said.

Gregory Brew, Eurasia Group’s senior Iran and energy analyst, said Iran now favors human spotters instead of relying on vulnerable coastal radars that U.S. airstrikes repeatedly targeted. Crew on small boats operating clandestinely among the fishing craft that crowd Hormuz can observe passing vessels and relay targeting information to missile and drone operators, surveillance that is difficult for U.S. forces to detect and disrupt. An Arab official familiar with Iranian attacks said such small boats often loitered around areas where attacks occurred.

Brew said, “They can keep it violent, they can keep risks to shipping high, they can keep costs high, they can keep oil prices high.”

Alessio Patalano, a maritime warfare expert at King’s College London, said, “Iran can inflict significant damage at little cost, while the ability to launch attacks from numerous coastal locations makes it harder and more time consuming for U.S. forces to detect and prevent them.”

The U.S. military runs near-daily operations to help ships and crude oil leave the strait while maintaining its blockade on Iran, The Wall Street Journal reported. The newspaper described the operations as an “expensive effort” that nevertheless recently returned flows to prewar levels.

The Trump administration insists it has control of the waterway, and the U.S. military in the region says it is cleared of Iranian mines. Adm. Brad Cooper, head of U.S. Central Command, said the military maintained its patrols through the narrow waterway after flying over the strait last week. Before the conflict, the strait was the conduit for 20% of the world’s oil supplies. “I didn’t see the IRGC out there, at all,” Cooper said, using an acronym for Iran’s Islamic Revolutionary Guard Corps.

A deal reached between Iran and the U.S. in June reopened the strait briefly, though Trump reinstated the U.S. blockade of Iranian ports as the two countries accused each other of violating the accord. The surge in attacks has coincided with signs that the recent recovery in shipping through Hormuz is faltering, although the latest oil-flow figures are preliminary and subject to upward revision.

According to ship tracker Kpler, oil flows through the strait, including associated ship-to-ship transfers, averaged around 7.8 million barrels a day in the week through Nov. 1, around 45% of prewar levels. Crude flows had reached close to prewar levels earlier in October.

Shipping crude from the Gulf to Asia cost nearly $37 a barrel in mid-October, more than five times prewar levels, according to the International Energy Agency, a Paris-based intergovernmental energy watchdog.

A spokesman for Iran’s foreign ministry did not respond to a request for comment. The attacks continued into November even as U.S. officials maintained patrols and said the waterway was clear of Iranian mines.