Sri Lanka, April 23 -- Oil prices jumped 4 percent Thursday after Iran vowed not to reopen the Strait of Hormuz so long as a US naval blockade remained in place despite a ceasefire extension.

At around 0025 GMT, the benchmark US oil contract West Texas Intermediate (WTI) climbed 4.06 percent to $96.73 per barrel.

International oil benchmark Brent North Sea crude rose 3.62 percent to $105.63. Both eased back in the following minutes.

Oil prices have soared since Israel and the United States attacked Iran on Feb. 28 and they have kept inching up on the uncertainty over whether war will resume.

As the clock ticked for a return to the war that has engulfed the region, US President Donald Trump had said Tuesday he would maintain the truce ...