Oil tanker traffic through the Strait of Hormuz was at a near standstill on Thursday, according to data and sources, as shipping risks escalated after the US renewed airstrikes on Iran, triggering retaliation by Tehran in the Gulf.
Just two tankers had so far sailed through the strait in the early hours of Thursday. They included the crude supertanker Berg 1, which had loaded at Iran's Kharg Island and is subject to US sanctions, according to analysis from Kpler.
The Marshall Islands-flagged chemical tanker Well Sail, also transited the strait, Kpler analysis showed. Its previous loading destination was near Sharjah in the United Arab Emirates, according to LSEG ship tracking data.
Shipping industry sources said vessels were increasingly switching off their public AIS tracking transponders, making it harder to see all of the ships crossing.
"Tanker traffic through the Strait of Hormuz has essentially stopped, which tells you more about risk perception right now than any statement from Washington or Tehran," Jorge Leon, head of geopolitical analysis at Rystad Energy, wrote in a report.
Iranian armed forces launched attacks on US military infrastructure in neighbouring Gulf states on Thursday in response to US strikes on Iran's southern coastal and eastern provinces, putting further strain on a three-week-old truce.
The latest flare-up in the four-month conflict began earlier this week with attacks on three tankers in the strait that the US blamed on Tehran.
Iran's Revolutionary Guards Navy said on Thursday that US attacks on Iran and intervention in redirecting shipping were disrupting the strait's gradual reopening, warning that any further US intervention would draw a "crushing response".
The Strait of Hormuz handled about a fifth of global oil supplies before the war erupted on February 28 with US and Israeli strikes against Iran.
Daily traffic in the past two weeks had risen to its highest levels since the war's outbreak, averaging 40 ships transiting the strait, which was still far off the pre-conflict average of 125 to 140 daily sailings.
Some war underwriters have advised shipping companies to pause voyages through the strait while others are reviewing their policy terms after the renewed vessel attacks, insurance industry sources told Reuters.
"The Hormuz reopening story looks more fragile after the latest escalation," ship broker Clarksons said in a report.
"As recent incidents have shown, the (marine war) market is now facing the prospect of potentially severe losses involving vessels of substantial value," said one marine war underwriter, who asked not to be named due to the sensitivity of the situation.
