A helicopter belonging to Saudi oil giant Aramco crashed on Sunday in Ras Tanura on Saudi Arabia's eastern coast west of the Strait of Hormuz, killing 14 nationals, the state news agency reported, adding that the cause was unknown.

Aramco had resumed crude oil loadings on Friday at its Ras Tanura terminal in the Gulf after they were halted for nearly four months.

"Investigations are under way, with the participation of relevant authorities, to determine the causes of the helicopter crash," the state news agency added.

Saudi Arabia, the world's biggest oil exporter, has joined ‌a rush to move cargoes after Middle East producers ramped up oil and gas output and exports ahead of an interim deal to halt the war between the United States and Iran.