Iran has delivered a shipment of aviation fuel to Myanmar and sent several tankers carrying liquefied petroleum gas (LPG), despite a US naval blockade.

Satellite imagery and analysis by maritime intelligence group SynMax showed an Iranian jet fuel tanker arriving at a Myanmar port in September, Reuters reports.

At the same time, Iran stepped up LPG deliveries, using tankers associated with its so-called shadow fleet and transferring cargo between vessels at sea.

The US imposed targeted sanctions on Myanmar’s aviation fuel sector in 2023 amid allegations that the country’s military used airstrikes against civilians and opposition forces. Myanmar’s military authorities have denied deliberately targeting civilians.

At least eight LPG tankers carrying Iranian cargoes had left the Gulf of Oman since mid-July, according to analysis by United Against Nuclear Iran (UANI). Six of those tankers, along with the jet fuel tanker that reached Myanmar, were under US sanctions for transporting Iranian petroleum products.

The US military has described its blockade as “ironclad,” while a US official said that a vessel’s passage does not necessarily mean it evaded the blockade, as ships are assessed individually and some may be allowed through under certain conditions.