The US military carried out a 13th consecutive night of strikes on Iran, saying the attacks are aimed at degrading Tehran’s ability to threaten civilian mariners and commercial vessels transiting through the Strait of Hormuz.

The escalation came after Yemen’s Iran-backed Houthi rebels claimed attacks on two Saudi oil tankers in the Red Sea, raising concerns over disruptions to another major shipping route. President Donald Trump warned the Houthis of severe military action if attacks on ships continue and said Iran would be held responsible.

Brent crude oil prices rose by more than six per cent to around 100 US dollars a barrel amid fears of prolonged disruptions to global energy supplies. This is the highest level since May, before the two sides reached a preliminary peace agreement last month that later collapsed.

United Nations Secretary-General António Guterres said diplomacy is the only way forward, while Iraq appealed for dialogue. Iran said 55 people have been killed and 629 injured since renewed US airstrikes began on 27 June.