Hormuz tanker attacks reach reported wartime weekly high

Three maritime-security sources counted at least 12 attacks on oil, LNG and LPG tankers around the Strait of Hormuz from September 28 to October 5, Reuters reported on October 7. The sources described it as the highest weekly count since the Iran war began on February 28. The count establishes a reported increase in attacks during that week; it does not establish that transit stopped.

What the incident counts show

The International Maritime Organization’s public list, stated as current to October 6, names nine vessels damaged between September 28 and October 4. Reuters reported that the IMO counted nine incidents for the September 28–October 5 period, compared with eight in its next-highest comparable week, beginning July 13. The maritime-security sources said IMO verification can take longer. It remains uncertain whether the IMO will confirm more incidents from the latest period or whether every event in the sources’ count meets the same definition of an attack.

The IMO listed 93 confirmed incidents and 24 seafarer fatalities over the conflict through October 6. Those cumulative totals do not describe casualties from the nine recently listed incidents.

Reuters also quoted the U.S. Navy-led Joint Maritime Information Center as reporting persistent attacks, attempted attacks and harassment, including drone overflights and radio hailing, by Iran’s Revolutionary Guards. That assessment does not identify the perpetrator of every attack in the maritime sources’ weekly count.

Crew safety and energy shipments

A separate strike on October 6 shows that crew injuries continued after the counted week. India’s Ministry of External Affairs said an unidentified projectile hit the Panama-flagged MT On Peace while it transited Hormuz. Twelve of its 19 crew members were injured, including 11 Indian nationals, and Omani authorities helped evacuate the injured. The ministry did not identify the projectile’s launcher.

The attacks create a direct safety risk for crews and a risk to oil and gas shipments. The available weekly counts do not quantify cargoes lost or delayed, and the October 6 injuries should not be added to the earlier period’s incident count.

For scale, the U.S. Energy Information Administration estimates that oil flows through Hormuz averaged 21.6 million barrels per day in the fourth quarter of 2025, before the war, and 4.9 million in the second quarter of 2026. Those quarterly averages show the corridor’s importance and the scale of the earlier decline. They do not measure traffic during the reported attack week or establish how much of the decline resulted from attacks.

Oil prices and stock releases

Brent futures settled at $100.20 a barrel on October 7, down $0.38 that day. The settlement does not support a claim that the reported weekly high drove crude prices up on October 7. The incident count alone also cannot measure an effect on fuel prices or inflation.

On the same day, International Energy Agency member governments backed accelerating oil-stock releases pledged in March and prioritizing diesel where possible. The IEA said roughly 100 million barrels of those pledges remained unreleased. The decision concerned the timing and composition of previously pledged supply, not an additional 100-million-barrel commitment.