Four liquefied natural gas (LNG) tankers controlled by Qatar entered the Strait of Hormuz on Monday, despite a sharp decline in shipping traffic following Iran's renewed declaration that the strategic waterway is closed.
Shipping data from analytics firm Kpler showed that the vessels Wadi Al Sail, Mekaines, Al Sadd and Mesaimeer transited the strait via the Iranian route for the first time since the outbreak of the conflict involving Iran, Israel and the United States earlier this year.
The move comes amid heightened tensions in the region and uncertainty over the security of one of the world's most important energy transit routes.
Qatar Energy, whose LNG exports have been significantly disrupted since the conflict began on February 28, did not immediately respond to requests for comment.
Data from the London Stock Exchange Group (LSEG) also showed that the Marshall Islands-flagged dry bulk vessel Summit Success entered the Gulf on Monday.
However, overall ship traffic through the strait has declined sharply. Kpler data showed that only five vessels passed through the waterway on Sunday, down from 26 ships the previous day.
Among the vessels that transited on Sunday were three Very Large Crude Carriers (VLCCs), each carrying about two million barrels of Saudi Arabian crude oil and fuel oil, with one vessel reportedly bound for Japan.
Industry analysts caution that the actual number of ships using the strait could be higher, as some vessels may be sailing with their tracking transponders switched off.
Iran had eased its effective blockade of the Strait of Hormuz last week after agreeing with the United States to extend an April ceasefire by 60 days to allow for peace negotiations.
However, the Islamic Revolutionary Guard Corps announced on Saturday that the strait would once again be closed in response to Israeli military strikes in Lebanon.
Despite the renewed tensions, oil exports have continued to flow through the region.
The United States Central Command said 55 merchant ships carrying more than 17 million barrels of oil transited the strait on Saturday.
Shipping data showed that vessels exiting the waterway included three VLCCs carrying crude oil from the United Arab Emirates, Kuwait and Iraq, as well as three tankers transporting refined petroleum products.
A further 13 vessels entered the strait on the same day, including two VLCCs.
Meanwhile, Iran says its oil exports remain resilient. National Iranian Oil Company head Hamid Bovard told state television that more than 25 million barrels of Iranian crude had crossed what he described as the "virtual blockade line" since Monday.
Three sanctioned VLCCs Elva, Virgo and Vigor carrying Iranian oil loaded at Kharg Island between late April and early May were also seen exiting the strait on Monday, according to Kpler and LSEG data.
The uncertainty surrounding the Strait of Hormuz has prompted Gulf energy producers to consider alternative loading options.
Abu Dhabi National Oil Company and Kuwait Petroleum Corporation have issued tenders offering buyers the option of loading crude either inside or outside the strait.
South Korea's Ministry of Oceans and Fisheries said two South Korean-operated vessels successfully passed through the waterway last week following the interim ceasefire agreement, although the ships were not identified.
Meanwhile, the Japan Shipowners Association said the number of Japanese-linked vessels remaining in the Gulf has dropped from 45 at the start of the conflict to 37, reflecting ongoing caution among international shipping operators as tensions in the region persist.