Brent crude futures rose $4.16, or 4.6%, to settle at $94.65 a barrel, while US West Texas Intermediate (WTI) gained $4.46, or 5.2%, to close at $90.22.

The gains pushed Brent to its highest level since July 24 and WTI to its strongest since July 23.

The latest rally followed a new wave of US airstrikes on Iranian targets, raising concerns that last weekend's exchange of attacks could develop into a prolonged conflict.

Oil prices had already risen after the initial attacks and reports that two tankers were hit while leaving the Strait of Hormuz, a vital route for global oil supplies that Iran has effectively closed to shipping.

Iran has vowed to prevent oil exports from the Gulf, while US President Donald Trump threatened to strike Iran "hard" in response to renewed Iranian attacks. US Treasury Secretary Scott Bessent also warned of new sanctions against Tehran.

The US Central Command said American forces had begun striking Islamic Revolutionary Guard Corps targets in Iran, following what it described as attempted attacks on commercial shipping in the Strait of Hormuz and US personnel in the region.

Analysts said the renewed fighting had increased concerns over prolonged disruptions to energy flows through the strategically important waterway.

Diesel prices surge

Disruptions at refineries, particularly in the Middle East and Russia, have also pushed diesel prices sharply higher.

In the United States, diesel futures climbed to a 52-month high on Tuesday after rising 51% over the past 10 weeks. The diesel-crude refining margin also reached a record high of around $107 a barrel, according to LSEG data.

Meanwhile, Russia's role in global oil supplies remained under focus after Russian airstrikes killed 12 people and injured many others in Kyiv and surrounding areas.

Russia was the world's third-largest crude oil producer in 2025, behind the United States and Saudi Arabia, and is a member of the OPEC+ group of oil-producing countries.

US oil inventories in focus

Markets were also awaiting weekly US oil inventory data from the American Petroleum Institute and the US Energy Information Administration.

Analysts expect US energy companies to have withdrawn around 800,000 barrels of crude from storage during the week ending August 28.

If confirmed, it would mark the first weekly decline in US crude inventories in five weeks.