Several oil tankers have abruptly changed course near Yemen after the Iran-backed Houthi movement announced a new “maritime embargo” targeting Saudi Arabia, raising fresh concerns over global energy supplies and shipping security in one of the world’s busiest trade corridors.

Ship-tracking data shows that at least seven oil tankers made sharp U-turns after Monday’s announcement, with all the affected vessels either heading to or departing from Saudi Arabian ports.

The latest disruption comes as the Red Sea has become increasingly important for global oil exports following the effective closure of the Strait of Hormuz during the recent US-Israel conflict with Iran.

Nearly 15 per cent of global maritime trade passes through the Red Sea, linking the Mediterranean Sea and the Gulf of Aden through the Suez Canal in Egypt and the Bab al-Mandab Strait between Yemen and the Horn of Africa.

The route has become a critical alternative for Saudi oil exports after traffic through the Strait of Hormuz was severely disrupted.

Rosemary Kelanic of the US-based Defense Priorities think tank said the Red Sea had played a “major role in relieving pressure to global markets” and warned that further Houthi restrictions would likely push energy prices higher.

According to maritime intelligence company Kpler, 20 vessels entered the Red Sea through the Bab al-Mandab Strait the day before the Houthis announced the embargo, while 22 ships exited the waterway.

Kelanic warned that attacks on vessels in the Red Sea or Gulf of Aden would not only affect ships linked to Saudi Arabia but could disrupt broader international maritime traffic.

The European Union’s naval mission in the region, Aspides, reportedly advised that “merchant vessels linked to Israeli, US or Saudi interests avoid transiting the Red Sea and Gulf of Aden until the threat level decreases,” according to an advisory cited by Reuters.

Ship-tracking data from MarineTraffic revealed that the Liberian-flagged crude oil tanker Rodos, carrying Saudi crude to India, departed the Red Sea port of Al-Muajiz on Monday evening and initially sailed south toward the Bab al-Mandab Strait before making a complete U-turn approximately nine hours later.

Another Liberian-flagged vessel, the oil and chemical tanker Mica, left Saudi Arabia’s Jazan port and also reversed course after heading south.

MarineTraffic data further indicates that at least eight ships approaching the Red Sea from the south also abandoned their routes before entering the Bab al-Mandab Strait.

Among them was the Marshall Islands-flagged vehicle carrier Liu Jiang Kou, which had been travelling from China to Saudi Arabia’s Jeddah port before changing course in the Gulf of Aden.

The Hong Kong-flagged crude oil tanker New Prime, also travelling from China to Saudi Arabia, similarly turned around and is currently reported to be waiting in the Arabian Sea.

Although the precise reasons behind each course change cannot be independently confirmed, maritime risk management company Vanguard noted that “the timing is consistent with the embargo announcement.”

According to an email sent by the Houthis to shipowners and seen by the BBC, “vessels are banned from loading or discharging cargo at any Saudi ports.”

The message further warned that ships “may be subject to targeting in any location within the operational reach.”

The Houthis say the embargo is retaliation for what they describe as a Saudi blockade of ports and airports in areas under their control in northwestern Yemen.

Saudi Arabia has rejected the accusation and pledged to “take all necessary measures to protect its ships in accordance with international law.”

Yemen has remained embroiled in civil war since 2014 after the Houthis seized the capital, Sana’a. The conflict escalated in 2015 when a Saudi-led coalition intervened in support of the internationally recognised government.

Although an informal truce has existed between Saudi Arabia and the Houthis since 2022, tensions have recently intensified.

Last week, the Houthis launched missiles at an airport in southwestern Saudi Arabia in response to air strikes on Sana’a airport, which they blamed on the kingdom.

The group has previously demonstrated its ability to disrupt shipping through the Bab al-Mandab Strait.

Following the outbreak of the Gaza war in October 2023, Houthi forces began attacking commercial vessels in the Red Sea and Gulf of Aden, claiming they were acting in solidarity with Palestinians.

Those attacks resulted in four ships being sunk, one vessel being seized and the deaths of nine crew members.

Since shipping through the Strait of Hormuz became restricted, Saudi Arabia has redirected more than 70 per cent of its crude exports to the Red Sea port of Yanbu using its east-west pipeline network.

According to Kpler and Signal Ocean, approximately four million barrels of crude oil per day have recently been shipped from Yanbu, compared with around 973,000 barrels daily a year earlier.

Kpler senior oil analyst Naveen Das said that if the Bab al-Mandab Strait becomes effectively inaccessible, Saudi Arabia’s remaining option would be to transport oil through the Mediterranean before routing shipments around the southern tip of Africa to Asian markets.

Das noted that consumers may not immediately feel the effects, but warned that the current geopolitical environment has made global energy markets more vulnerable.

“We could weather it for two weeks, three weeks, even a month, but even in that time, we will see higher freight rates, higher energy prices and that bleeds into higher energy consumer costs.”

To reduce the risk of being targeted, many vessels operating near the Red Sea have begun broadcasting messages declaring that armed security personnel are on board, a practice that became common during previous Houthi attacks linked to the Gaza conflict.

MarineTraffic data indicates that at least 50 vessels in the region are currently transmitting such security messages.

Martin Kelly of EOS Risk Group said ship captains fear the Houthis could mistakenly identify vessels based on previous visits to Saudi ports.

“Houthis might read your situation wrong” and think their ships have “called at a Saudi port in the past, then therefore you could be attacked”.

He also warned of the potentially devastating consequences if one of the large crude carriers were successfully targeted.

“A lot of these ships are very large crude oil carriers. I think the damage would be catastrophic. There would certainly be deaths onboard these ships.”

Ukraine has carried out another wave of drone strikes targeting warehouses owned by Russia’s largest online retailer, Wildberries, leaving at least 15 people injured and forcing workers to evacuate two major logistics hubs.

The latest attacks come just days after Ukrainian drones struck other Wildberries facilities in Tambov and Elektrostal, where eight people were reportedly killed.

According to Wildberries founder Tatyana Kim and regional officials, logistics centres in Krasnodar and Nevinnomyssk in Russia’s Stavropol region were hit during overnight attacks, disrupting operations at the company’s facilities.

Ukrainian President Volodymyr Zelensky confirmed the strikes, saying the targeted sites were linked to Russia’s military supply chain.

“Ukraine had hit logistics hubs in the Krasnodar and Stavropol regions involved in providing the Russian army with drone components, navigation equipment and other gear,” Zelensky said on Wednesday.

Following the attacks, Wildberries evacuated workers from the affected warehouses.

Reacting to the incident, the company’s founder, Tatyana Kim, condemned the attacks and expressed concern for employees.

“There are no words to describe all the feelings and emotions caused by the attacks on ordinary people, on our employees, on us, who are simply doing our jobs,” she wrote on Telegram.

“But these situations demonstrate the most important thing: we must continue to do what we do for the benefit of people.”

Authorities in Stavropol said five people sustained injuries at the Nevinnomyssk warehouse complex and were treated as outpatients.

In Krasnodar, Governor Veniamin Kondratyev confirmed that ten people were injured after drones struck another warehouse complex, with three victims reported to be in serious condition.

BBC Verify analysed available footage and confirmed fires at both logistics centres.

Reports of the attacks began shortly after midnight GMT, with Russia’s state news agency TASS reporting that air defence systems had been activated in Nevinnomyssk before videos showing massive explosions and fires surfaced online.

Footage from the scenes showed extensive fires engulfing warehouse buildings while thick black smoke billowed into the sky.

Governor Kondratyev described the overnight assault on Krasnodar as a “massive attack,” adding that drone debris struck a company facility in Armavir, killing one employee.

He also confirmed that an oil depot caught fire during the strikes, while fragments from intercepted drones damaged two apartment buildings in Krasnodar and two homes in Dinskaya village. No civilian injuries were reported from those incidents.

Zelensky also claimed Ukrainian forces targeted an oil depot, a tanker and four cargo vessels belonging to Russia’s so-called shadow fleet operating in the Sea of Azov and the Black Sea.

Russia has relied on a “shadow fleet” to move oil exports while attempting to bypass international sanctions imposed after the country’s full-scale invasion of Ukraine in 2022.

The latest attacks mark the second time in less than a week that Wildberries’ logistics infrastructure has been targeted.

Satellite imagery released after the earlier strikes showed extensive destruction at the company’s warehouse complex in Elektrostal, near Moscow, where several buildings were completely destroyed by fire.

Serhii Kuzan, chairman of the Ukrainian Security and Cooperation Centre, previously told the BBC that Wildberries had become a logistics channel for military-related purchases.

“The primary rationale for striking Wildberries’ warehouses is to disrupt Russian logistics and the supply of dual-use goods, critical electronics, sanctioned goods and the like to the Russian army and Russian arms manufacturers,” he said.

“The collateral damage from such strikes could also have a serious impact on the Russian economy, as well as a psychological effect on Russian society and, likely, on continued support for the war.”

Unlike Amazon, Wildberries and its competitor Ozon primarily operate as online marketplaces, connecting independent merchants with customers while providing storage, delivery and payment processing services.

The repeated attacks have disrupted the livelihoods of hundreds of small business owners who depend on the platform.

One seller, identified only as Elena, told BBC Russian that the clothing she sells was destroyed in the strikes, leaving her without a source of income.

“If there are more strikes, I probably won’t manage. It’s terrifying to keep loading my goods into what feels like a furnace,” she said.