LONDON, April 28 -- Six tankers loaded with Iranian oil have been forced back to Iran by the US 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. Between 125 and 140 ships usually crossed in and out of the strait daily before the US-Israeli war on Iran began on February 28, but only seven have done so in the past day, according to Kpler ship-tracking data and satellite analysis from SynMax, and none carrying oil bound for the global market. They included the Iranian-flagged dry bulk vessel Bavand which left from an Iranian port, and other vessels leaving from Iraqi ports, the data showed. Iran has imposed restrictions on...