Oil surged as much as 5% after the broadest and bloodiest attack on Israel in decades threatened to inflame tensions in the Middle East, the source of around a third of the world’s crude. West Texas Intermediate traded near $86 a barrel as a war-risk premium returned to markets. The death toll on both sides following Hamas’ strikes against Israel over the weekend topped 1,100 as fighting headed into a third day, while the US said it was sending warships to the region.