Oil prices rose more than 2% on Monday after the United States struck two Iranian launchers on Larak Island in the Strait of Hormuz, followed by an Iranian attack on two US air bases in Jordan, according to Iranian media citing the Revolutionary Guards.

Brent crude futures climbed $2.51, or 2.85%, to $90.61 a barrel as of 0241 GMT. US West Texas Intermediate crude rose $2.13, or 2.55%, to $85.53 a barrel.

Fresh attacks raise supply concerns

The latest military escalation has added to concerns about oil supplies through the Strait of Hormuz, through which around a fifth of the world’s oil flowed before the conflict began in late February.

US forces struck the Iranian launchers on Sunday, marking the first known American strikes on Iran since late July. Iran subsequently attacked two US air bases in Jordan, according to Iranian reports.

“Looks like we are in another escalation phase,” IG market analyst Tony Sycamore said, adding that it was difficult to predict whether the escalation would last days or weeks.

Strait of Hormuz remains critical

Negotiations to end the conflict remain stalled as mediators work to reopen the strategically important waterway. While oil flows through the strait have increased, helping ease immediate fears of major supply disruptions, shipping activity remains subdued.

Shipping data showed that only five visible commodity vessels a day passed through the Strait of Hormuz over the weekend, reflecting increased caution among shipping companies.

The United Kingdom Maritime Trade Operations also reported that a tanker was struck by a projectile while travelling inbound through the strait on Saturday.

Oil markets watch next moves

Analysts said WTI could rise further if it breaks through resistance around $85.80-$85.90 a barrel. The next potential levels are last week’s $87.69 high and July’s $93.50 high.

Meanwhile, US Treasury Secretary Scott Bessent said Washington is likely to impose new secondary sanctions on Iran each week, aimed at increasing pressure on Tehran and cutting the country off from the dollar-based financial system.

Despite Monday’s rise, Brent and WTI remain set for small monthly declines in August after falling more than 4% last week.