Three oil tankers have made U-turns in the southern Red Sea after warnings from Houthi rebels in Yemen that they would target ships heading to or from Saudi ports.

One of those vessels, the very large crude carrier Xin Long Yang, left the port of Yanbu on July 20, hauling about 2 million barrels of Saudi crude to China. It came to a halt before reaching the Yemeni border on the morning of July 21, and was last seen heading north, according to ship-tracking data compiled by Bloomberg. 

The VLCC Xin Long Yang makes a U-turn in the southern Red Sea after Houthi rebels in Yemen warn they’ll attack ships calling at Saudi ports. Source: Bloomberg

The diversions underline how threats by Houthi rebels risk curbing Saudi oil exports from the Red Sea hub that has become a crucial workaround since the Iran war severely disrupted shipping out of Persian Gulf ports.

An aframax tanker named Rodos, managed by Dynacom Tankers Management Ltd. and carrying about 700,000 barrels, also abandoned its original voyage toward India, switching its destination from Mangalore to the Suez Canal after reversing course. The Greek operator has already seen two of its vessels attacked while crossing the Strait of Hormuz in recent days.

The Pakistani tanker Lahore, carrying crude to Karachi, also appears to have suspended its voyage after departing Yanbu on July 20. 

The tankers could make the much longer voyage to Asia via the Suez Canal and the west coast of Africa. However, the supertanker would have to offload about half its cargo into the Sumed pipeline that crosses Egypt from the Red Sea to its Mediterranean coast, before it could transit the canal. They would then reload at Sidi Kerir before continuing their voyage. That would increase the length of the voyage from about 7,000 miles to more than 17,000 miles.

The original route to China would take them through the Bab el Mandeb strait, a narrow passage of water linking the Red Sea to the Gulf of Aden and the Arabian Sea. Houthi rebels in Yemen issued a warning on July 20 that they would resume earlier attacks on shipping in the area, specifically targeting tankers calling at Saudi ports.

The development comes on the heels of the breakdown in an interim peace deal between the U.S. and Iran that has seen Tehran attack shipping using the Strait of Hormuz and U.S. bases in neighboring countries, while Washington has launched repeated attacks on Iranian territory.

The Equasis maritime database shows the Xin Long Yang is managed by Shanghai-based Cosco Shipping. There was no response to emails to the company outside normal working hours. Dynacom and Lahore’s owner, the Pakistan National Shipping Corp., didn’t immediately respond to emailed requests for comment.