Shipping group says Houthis sent radio warning to vessels

The International Chamber of Shipping said Yemen's Iran-backed Houthis were recorded sending a radio warning to ships after the group announced a maritime embargo of Saudi Arabia.

The Houthis announced the embargo on Monday. The source report described the move as an escalation of the US-Iran war and said it threatened global oil markets by trying to restrict Saudi Arabia's ability to bypass the Strait of Hormuz and reach global markets.

Christopher Long, intelligence director at international risk management and maritime security company Neptune P2P Group, said the message was recorded by a ship in the Bab el-Mandeb Strait on Monday. The message warned ships belonging to Saudi Arabia not to proceed through the Red Sea and Gulf of Aden, and said non-compliant ships would be targeted.

The Houthis have not said how they would enforce the blockade and have not so far attacked any ships.

Data analysed on Wednesday showed nine ships made a U-turn after the blockade was announced, although some later resumed course. Three vessels had been signalling destinations in Qinzhou and Tianjin in China and New Mangalore in India before reversing on Tuesday while heading south toward Bab el-Mandeb. One of them turned around again a few hours later and on Wednesday was continuing toward the strait.

Six other vessels were on the opposite side of the passage, in the Gulf of Aden or Arabian Sea, when they turned back. They included two container ships, a vehicle carrier, a loaded bulk carrier and two tankers, one of which was carrying cargo from the United Arab Emirates. Three of those ships later resumed their route toward Bab el-Mandeb.

The blockade, if enforced, could further strain Saudi Arabia's economy by cutting off access to its Red Sea ports. The report said those ports have been vital for oil exports as renewed fighting limits passage through the Strait of Hormuz.

The International Chamber of Shipping said any diversions after the Houthi announcement were made through individual risk assessments. It said the UK Maritime Trade Operations agency had not yet seen a decisive change in traffic frequency through Bab el-Mandeb.

According to Kpler, 44 vessels passed through the strait on July 20, the day the blockade was announced, and 29 passed through the following day. Over the previous five days, the daily maximum was 53 transits and the minimum was 30.

Kpler data also showed Saudi seaborne crude exports through Bab el-Mandeb rose eightfold between March and mid-July 2026 compared with the same period in 2025. Exports through the route reached nearly 100 million barrels in June, compared with 7 million barrels in February.

After the war started, the Red Sea port of Yanbu became crucial to Saudi seaborne crude exports. Kpler data showed all Saudi seaborne crude exports departed from Yanbu in April and May. The port accounted for 92 percent of such exports in June and 78 percent so far in July.