Oil prices have jumped sharply after renewed fighting between the US and Iran prompted fresh concerns over disruption to global energy supplies through the Strait of Hormuz.
Brent crude climbed more than 9% to $83.30 a barrel yesterday, its highest level in a month and its biggest single-day dollar gain since early April, and has continued to rise this morning.
Brent had been trading at around $71 a barrel at the start of July following hopes of a lasting ceasefire.
The increase came after President Donald Trump said the US would reinstate a naval blockade against Iran after the latest military exchanges.
Iran also claimed to have closed the Strait of Hormuz, through which around a fifth of global oil supplies passed before the conflict began.
According to MarineTraffic, no commercial vessels had passed through the waterway while broadcasting their location since Sunday evening.
The International Energy Agency estimates oil flows from the Gulf have fallen from 24 million barrels a day before the conflict to 16 million barrels a day last week.
The Times reports that higher oil prices have also pushed up government borrowing costs and increased expectations that central banks may need to keep interest rates higher for longer.