The ships’ attempt to transit the strait will clearly test how tightly the Houthis will impose the naval blockade on Saudi Arabia they announced on Monday.

The group said they attacked two Saudi tankers ​with drones and missiles earlier on Thursday.

The Red Sea blockade by the Iran-aligned Houthis threatens to further disrupt global ​energy supplies at the same time the key Strait of Hormuz has practically shut amid ⁠the resumption of fighting between the US and Iran.

The Singaporean-flagged VLCC Xin Long Yang, which made a U-turn and took a ​pause in the middle of the Red Sea on Tuesday, resumed its journey southward late on Wednesday, LSEG shipping data showed.

The ​vessel was sailing past the Yemeni coast and heading to the port of Qinzhou in southern China, the shipping data showed.

The Chinese-flagged VLCC Cosnew Lake was following, and it was signalling it would discharge its cargo at the port of Huizhou in the southern Chinese province of Guangdong, the data ​showed.

Both vessels indicated through their automatic identification system transmitters that there were Chinese crew onboard, the data showed.

The vessels are ​chartered by Unipec, the trading arm of Asia’s largest refiner Sinopec, and loaded crude at Saudi Arabia’s port of Yanbu earlier this week.

Cosco Shipping, ‌which manages ⁠both tankers, and Sinopec did not immediately respond to requests for comment.

Hormuz transits

Earlier on Thursday, the Houthis announced they had carried out a military operation targeting two Saudi oil tankers they said violated the blockade.

The Saudi Arabian news agency SPA later said the Saudi vessel Encelia was attacked in the Red Sea and was on fire, though the crew was safe.

Because of the ​Middle East conflict, shipping traffic ​through the Bab El Mandeb ⁠declined and movement through the Strait of Hormuz remained subdued on Wednesday, LSEG and Kpler data showed.

Twenty-seven vessels, including five oil tankers and a liquefied petroleum gas (LPG) carrier, crossed the Bab El Mandeb strait on Wednesday, LSEG data showed, down from 38 the previous day.

Three vessels transited ​the Strait of ⁠Hormuz on Wednesday, down from four a day earlier and 18 the previous Wednesday, according to data analytics firm Kpler.

Two vessels entered the strait from the Gulf of Oman, including a tanker carrying dirty petroleum products that sailed through Iranian waters and a dry ⁠bulk carrier ​operating in dark mode, with its tracking signal switched off, Kpler data ​showed.

As of July 20, there were 253 laden tankers in the Gulf, including 102 oil tankers, 64 liquefied natural gas carriers and 66 liquefied petroleum gas ​carriers, according to LSEG data.