A Saudi airline has resumed flights for Iranian hajj pilgrims to the kingdom for the first time in a decade, the latest sign of the warming ties between the countries.

"Flynas resumed Iranian pilgrims flights from Imam Khomeini (airport) in Tehran on Saturday," a Saudi civil aviation authority official told AFP, speaking on condition of anonymity.

The official said flights would also be added from Mashhad in Iran, allowing more than 35,000 pilgrims to travel to Saudi Arabia on the airline.

The official stressed that the flights were not commercial and were only for the hajj pilgrimage.

The hajj is due to begin during the first week of June, and pilgrims from across the globe have already begun pouring into Saudi Arabia.