Tanker Attacks Cut Hormuz Traffic as Iran Threatens Wider Shipping Restrictions

The latest escalation followed a recovery in oil shipments through the Strait of Hormuz. But that recovery was taking place alongside repeated attacks: CNBC reported on October 6 that nearly 20 commercial ships, mostly tankers, had come under attack over the previous month.

Iran was also warning individual vessels away. On October 5, The Times of India reported an Iranian Revolutionary Guard Corps threat telling a tanker to turn back or be targeted. The following day, Marine Insight reported four tanker attacks and a threat against another vessel.

On October 6, US President Donald Trump said that "millions of barrels" of oil had passed through Hormuz in recent days, according to Middle East Eye. Al Jazeera also reported rising Gulf oil flows, while questioning whether the increase could last amid escalating attacks.

By October 7, the scale of the violence was becoming clearer. The Japan Times reported that U.K. Maritime Trade Operations had recorded nine attacks already that month, half its total for all of September. Middle East Eye reported that attacks on tankers the previous week had reached their highest weekly level since the Iran war began.

Iran hardened its public position that day. Senior Iranian Commander Brigadier General Naghdi said the strait remained closed and under the full control of Iran's armed forces until its demands were met, according to Mehr News. Separately, CBS reported an IRGC official saying Iran would soon block routes it deemed illegal.

Also on October 7, a tanker off Qatar reported being struck by multiple projectiles, causing an unspecified number of casualties, Arab News reported, citing the UKMTO maritime agency. On October 8, Euronews reported that two commercial vessels had been hit within 24 hours, one off Qatar and another off Fujairah in the Gulf of Oman. Its report described signs of an expanding campaign beyond Hormuz.

The shipping figures published on October 8 showed a sharp slowdown. Only seven commodity vessels passed through the strait on October 6, the lowest daily figure since July 23, according to Kpler data reported by The Hindu. Business Line reported that crude oil crossing the strait had fallen 27% from its Iran war high.

Iran's claim that Hormuz is closed does not mean all passage has stopped. The reported crossings show vessels are still moving through, but at sharply reduced levels. The Financial Times reported on October 8 that transit had risen close to 90% of prewar levels last month before falling sharply.

Oil prices are rising again. CNN linked the October 8 increase to supply worries following record tanker attacks and reduced crossings. Hormuz is not the only pressure on prices: CNBC reported a day earlier that concerns over Houthi attacks on Saudi Arabia were outweighing the recovery in Middle Eastern crude supply.

The immediate issue is whether Iran carries out its stated plan to block additional routes, reported by CBS. Further attacks outside Hormuz would also test whether the incidents off Qatar and Fujairah mark a sustained widening of the campaign described by Euronews.

The next shipping figures will show whether the October 6 low was temporary or the beginning of a deeper disruption. Another pending issue is the US response: NBC News reported on October 8 that President Donald Trump was weighing whether to resume large-scale US military operations in Iran in the coming weeks.