The need to know for the week starting April 27 2026 The key supply chain stories from Reuters’ global network of journalists Iran oil tankers turned back by US blockade, Hormuz traffic sparse Six tankers loaded with Iranian oil have been forced back to Iran by the U.S. blockade in recent days, ship-tracking data shows, underscoring the impact the Iran war is having on traffic through the Strait of Hormuz, a major global oil export route.