The US said it had struck around 140 targets on Saturday in response to the Iranian military striking a vessel which was navigating through the international waterway.

Tehran reportedly launched a series of attacks targeting a US base in Jordan on Sunday, while the United Arab Emirates, Bahrain, Oman and Kuwait said they had come under attack by missiles and drones from Iran.

‘Deeply concerned’

UN Secretary-General António Guterres said he was “deeply concerned by the serious escalation,” urging an end to all attacks.

A statement issued by his Spokesperson called on all combatants “to exercise maximum restraint, avoid further escalatory action and take immediate steps to de‑escalate.”

The Secretary-General reiterated that a return to full-scale hostilities would have catastrophic consequences “for the peoples of the region” and beyond, as well as the global economy.

The uptick in fighting and end to the fragile ceasefire negotiated last month have seen energy prices rise while shipping through the strait between Iran and Oman has once again ground to a halt.

Freedom of navigation call

This leaves around 6,000 seafarers still stranded aboard scores of vessels. The head of the UN International Maritime Organization (IMO) called for all transit through the strait to be avoided, saying earlier this week that this should continue “until the necessary safety conditions are in place.”

UN chief Guterres added that “full freedom of navigation” must be restored in the Strait of Hormuz, where three merchant ships were reportedly struck the previous Tuesday, despite the 17 June Memorandum of Understanding between Tehran and Washington.

“The Secretary-General urges Iran and the United States to urgently resume negotiations and to address outstanding issues through diplomacy,” said UN Spokesperson Stéphane Dujarric.