Saudi Arabia's King Salman bin Abdulaziz, 84, underwent a successful surgery to remove his gall bladder in the capital Riyadh.

SPA, the official Saudi Press Agency, said the laparoscopic surgery performed on him was a success and that he will remain in hospital for some time for recuperation.

Crown Prince Mohammed bin Salman — known as MbS — is the de facto ruler and next in line to the Saudi throne. He was appointed to his role after staging a palace coup three years ago which saw the removal of former Crown Prince Mohammed bin Nayef.

He has won praise at home for easing social restrictions in the conservative Muslim kingdom, giving more rights to women and pledging to diversify the economy.

The maverick price has, however, been criticised for Saudi involvement in Yemen's civil war and attempts to silence dissident and consolidate power by marginalising rivals, including a purge of top royals and businessmen on corruption charges.

MbS’s image has also been severely tarnished following the murder of journalist Jamal Khashoggi in Istanbul in 2018 at the hands of Saudi security personnel seen as close to him.

Saudi stability is vital to the security of oil supplies since it ranks as the world’s largest oil exporter, which also keeps a significant spare capacity to ensure stable oil prices.