Oil prices jumped 4 per cent on Thursday amid vows by Iran not to reopen the Strait of Hormuz so long as the US naval blockade of Iranian ports remains in place.
At about 00:25 GMT, the benchmark US oil contract West Texas Intermediate (WTI) climbed 4.06 per cent to $96.73 per barrel.
International oil benchmark Brent North Sea crude rose 3.62 per cent to $105.63. Both eased back in the following minutes. Oil prices continue to rise and fall slightly on the uncertainty over whether war will resume.