Both benchmarks had already climbed about 3 per cent on Tuesday after Washington revoked the general licence that had authorised the sale of Iranian crude following the reported attacks.

Last month, after the US and Iran reached a truce agreement, oil prices had retreated to pre-war levels as traders built large short positions in oil futures, betting prices would continue to fall.

Security threat raised to ‘severe’

The spike in oil and gas prices came after a Qatari LNG tanker faced the risk of explosion and a Saudi crude tanker was damaged near the Strait of Hormuz on Tuesday. The attacks prompted the United Kingdom Maritime Trade Operations to raise the security threat level for vessels passing through the waterway to “severe”, Reuters reported.

The US Navy-led Joint Maritime Information Center (JMIC) also elevated the threat level from “substantial” to “severe”, citing deliberate hostile action under current conditions. It marked the first time since June 15 that the threat level had been raised to its highest category.

“The recent confirmed incidents highlight that the threat environment remains heightened and warrants extreme vigilance,” JMIC said in an advisory. It also warned mariners to expect continued naval deployments, congestion along transit routes and increased hailing by the Islamic Revolutionary Guard Corps.

Licence revoked

On Tuesday, the White House also revoked a licence it had granted Iran to sell oil as part of efforts to ease tensions.

Washington said Iran’s actions in the Strait of Hormuz were unacceptable and warned they would carry consequences. The licence, granted in June, had temporarily eased decades-old sanctions as part of an agreement to reopen the strategic waterway.