Iran Expands Hormuz Surveillance as Attacks Escalate and Oil Flows Slump Again

Iran's military says it has expanded surveillance of the Strait of Hormuz by deploying new units targeting vessels, as Tehran and Washington compete for control of the world's most critical energy shipping lane.

With a US naval blockade on Iran's southern ports and tightening sanctions, Tehran has repeatedly said it will pursue military and diplomatic measures to pressure Washington into accepting its demands for reopening the strait.

Tehran's latest announcement coincides with rising attacks and falling oil shipping traffic, after crude flows had recovered to pre-war levels in September.

Chris Featherstone, a political scientist at the University of York in the UK, told Al Jazeera that the escalation and its impact on energy flows showed how fragile the strait is as a key oil export route.

So where do things stand, and who controls the Strait of Hormuz?

What has Iran said about expanding its Hormuz presence?

Iran's navy said it had deployed combat units in a new formation "east of the Strait of Hormuz and across the Sea of Oman and the Arabian Sea, after identifying a damaged and burning oil tanker," according to Press TV on Tuesday.

The navy said the units would maintain "real-time surveillance of enemy activities and maritime traffic in the area."

It also warned vessels not to switch off their transponders and urged them to coordinate with Iranian armed forces to pass through the area safely.

An Iranian official separately told Reuters that Tehran had begun using different attack tactics against vessels deemed to have violated its restrictions about 10 days ago, leading to the surge in strikes. The strategy includes changing both the type and tempo of attacks, with one aim being to influence the outcome of November's US midterm elections, according to the official.

Attacks in Hormuz hit record levels

Ships in the Strait of Hormuz are enduring the worst wave of attacks since the US and Israel launched war against Iran in late February.

According to maritime tracking firm Kpler, 10 tankers were hit in the strait between September 28 and October 4, followed by another strike on October 5.

The United Kingdom Maritime Trade Operations (UKMTO) recorded 15 further attacks between October 6 and October 14, 11 of them in the last four days alone. UKMTO said these included a container ship and an oil tanker struck by projectiles of unknown origin in the Strait of Hormuz on Tuesday.

Iran says the attacks and restrictions on the shipping lane are a matter of national security and self-defence against the US-Israeli war. Iranian officials have also hinted at an intent to disrupt the US-backed shuttle system that has boosted energy exports through the strait during the war.

In its latest report on Sunday, the US Navy-led Joint Maritime Information Center (JMIC) said the threat to commercial shipping in the Strait of Hormuz remained at "severe," its second-highest level. JMIC said attacks by Iran's Islamic Revolutionary Guard Corps (IRGC), "plotting and/or harassment activities continue, including drone overflights, deliberate surveillance of commercial vessels and occasional VHF calls."

UAVs are unmanned aerial vehicles, while VHF calls refer to Iranian forces using standard maritime radio to verbally contact, track and threaten commercial ships passing through on international channels.

How are the attacks affecting oil flows?

Before the US-Israeli war against Iran began on February 28, the Strait of Hormuz typically handled about 125 large commercial ships a day, with traffic through it accounting for roughly 20 percent of global crude and liquefied natural gas supply.

In retaliation for US-Israeli strikes, Iran has effectively closed the strait and stepped up attacks on ships trying to defy its rules. Washington, meanwhile, has maintained its blockade of Iranian ports.

In September, however, oil flows from the Gulf through Hormuz, excluding Iran, recovered to more than 81 percent of pre-war levels, while crude exports from the entire Middle East exceeded pre-war levels during the first 14 days of the month, according to Kpler. Escorted by the US Navy, more tankers began making the passage.

The Iranian threat meant crews were paid handsomely, insurance premiums remained very high, and some analysts suspect Gulf states may also have paid Iran to let tankers transit. That means that even as more oil was exported from the region, crude prices stayed high.

But Iran's escalating wave of attacks in recent days has changed the picture. According to Kpler, only 2.9 million barrels of oil were shipped through the sea lane on October 11, the lowest level of the month. As recently as October 8, nearly 20.8 million barrels passed through the strait. The pre-war average was 17.1 million barrels a day.

Oil prices continued to rise on Wednesday morning, with Brent crude futures up 89 cents, or 0.8 percent, at $106.58 a barrel as of 00:30 GMT. Brent settled at $105.69 a barrel on Tuesday, while West Texas Intermediate closed at $94.14.

What has the US said?

On Wednesday, a US military official confirmed to Reuters that Iran had significantly changed its tactics in the Strait of Hormuz. The official noted that after Washington destroyed much of Iran's radar capability, the IRGC began using unarmed spotters on small boats to identify potential targets, including US naval vessels.

The US military identified Iranian spotters operating from dhows, calling in targets for the IRGC, according to the official, and US forces confronted one such vessel, ordering those aboard to abandon ship before destroying it.

US Central Command (CENTCOM) also rejected a claim by an IRGC commander that Tehran controls the Strait of Hormuz and would sink advancing US warships. "The IRGC naval commander has no navy. US and regional partner forces clearly control the Strait of Hormuz," CENTCOM said on X. It added that US forces had helped Gulf partners ship more than 19 million barrels of crude through the strategic chokepoint on Monday.

So who controls Hormuz?

Since Iran effectively closed the Strait of Hormuz after the war began, the US Navy is said to have opened a route for Gulf states to export oil and other goods amid the energy crisis caused by Iranian attacks on ships.

Late on Sunday, Iranian security official Mohsen Rezaei claimed US Central Command, with support from the United Arab Emirates military, was using smaller vessels to transfer oil to larger tankers. He said the US shuttle system was a clear target for Tehran, and that Iran had attacked five to six ships taking part each night for weeks.

"You are smuggling, but the strait is under Iran's control, and we manage it," he said. The remarks appeared aimed at provoking US President Donald Trump, who has praised energy exports at times reaching pre-war levels in recent weeks.

Iran says the US has accepted some of Tehran's seven conditions for fully reopening the Strait of Hormuz and ending the war, but that Washington's response is "not enough." Tehran says a deal will only materialise when all its demands are met.

"The Trump administration has neither pushed for continued negotiations nor sought further support from potential intermediaries such as Qatar and Pakistan," said Chris Featherstone, a political scientist at the University of York. "For Iran, they may see this as a moment to ramp up pressure on the Trump administration."

He noted, however, that the strait is not under Iran's control, and that Tehran's attacks are only meant to show Washington does not control the sea lane either. "Therefore, US allies will increase pressure on the Trump administration to bring more stability to the region, or to show a path towards greater stability," he added.