The shipments most likely originated from Russia, were shipped to Estonia by rail and then re-exported. While fuel imports from Russia are permissible under EU law until December, it certainly raises some questions about Estonia's otherwise hawkish stance towards sanctions against Russian exports.
Saudi Arabia will have imported three cargoes of Estonian fuel oil in May and June, compared with only one in each of the preceding two years.
Russia needs to find new markets for its oil and fuel after sanctions levied against its exports following the invasion of Ukraine.
The shipments are small in the context of the global oil market, but underscore the close ties between Riyadh and Moscow.