Mohammed bin Salman “apologised for not being able to participate in the Arab Summit to be held on November 1 in Algiers, in accordance with the recommendations of doctors who advise him not to travel,” the official Algerian news agency APS said, citing a presidency statement.

Algerian President Abdelmadjid Tebboune responded during a phone call that “he understood the situation and regretted the crown prince’s inability to attend” the summit, expressing “wishes for his health and well-being.”

The story did not provide any explanation for the doctors’ recommendations.

Saudi officials did not respond to a request for comment. But Ali Shihabi, a Saudi analyst close to the government, said the concern could be related to an “ear condition”.

Prince Mohammed “has an endemic ear condition which makes long distance air travel difficult because the pressure in an aircraft can lead to ear blockage for weeks,” he said on Twitter.

“This explains how sometimes last minute he makes travel changes. Nothing major!”