Ships in the Gulf have received a warning from Iran’s navy that any vessels seeking to cross the Strait of Hormuz without permission “will be targeted and destroyed”, the shipping brokerage firm SSY has confirmed to BBC Verify.
A two-week ceasefire was agreed on Tuesday evening on the condition that “safe passage” through the narrow waterway is guaranteed – but only a few vessels have since crossed.
The strait has become a focal point of the US-Israel war with Iran after Tehran effectively choked off one of the world’s most important shipping lanes, carrying about a fifth of the world’s oil and liquefied natural gas.
The disruption, over the past five weeks, has sent shock waves across the world economy, pushing up energy prices and exposing just how reliant international supply chains are on the strait, which is only about 33km (21 miles) wide at its narrowest point.
As well as energy, the Gulf is also vital for transporting chemicals needed to process products like microchips, pharmaceuticals and fertiliser.
While the price of oil has fallen on news of the ceasefire, shipping analysts are warning to expect only a trickle of crossings for now.
“Most shipping lines would want to get details and reassurances on what it actually takes to transit and those details are not available,” Lars Jensen from Vespucci Maritime told the BBC.