Two vessels loaded with liquefied natural gas (LNG) from Ras Laffan, Qatar, turned back after they moved eastward towards the Strait ​of Hormuz, ship-tracking data showed on Monday.

Had the vessels successfully ‌crossed the strait, it would have been the first transit of LNG cargoes through the waterway since the U.S.-Israel war with Iran began on February 28.

Data ​from analytics firms Kpler and LSEG showed the vessels, Al ​Daayen and Rasheeda, loaded their cargoes in late February. The ⁠data also indicated that the Al Daayen tanker was signalling ​for China at the moment.

Additionally, Kpler data showed both tankers as controlled ​by QatarEnergy.

QatarEnergy did not immediately respond to a Reuters request for comment.

Previously, a Japanese LNG tanker, the Sohar LNG, managed to cross the strait, its joint owner Mitsui ​O.S.K. Lines said on Friday.

The tanker, however, was empty, and ​a company spokesperson declined to disclose when the passage took place or whether ‌any ⁠negotiations were involved.

It has been more than five weeks since the US and Israel began striking Iran in a war that has killed thousands and damaged economies by driving up oil prices, with tanker traffic ​through the Strait ​of Hormuz choked ⁠by the fighting and retaliatory attacks on a route that carries about a fifth of global oil ​and LNG flows.

Qatar is the world’s second-largest exporter of ​LNG, ⁠with shipments mostly going to buyers in Asia.

Iranian attacks, however, knocked out 17% of Qatar’s LNG export capacity, with repairs expected to sideline 12.8 ⁠million ​tonnes per year of the fuel for ​three to five years.