Saudi Arabian authorities have detained a brother and a nephew of Saudi King Salman bin Abdul-Aziz al-Saud Salman and accused them of treason, according to a person familiar with the matter — a move that extends a series of crackdowns on royal relatives by Crown Prince Mohammed bin Salman.

Former Crown Prince Mohammed bin Nayef — who had been in line to be king before being sidelined — and Prince Ahmed bin Abdulaziz al-Saud, a brother of the current king, were arrested on Friday, the person familiar with the matter said. Mohammed bin Nayef's brother, Nawaf, was also detained with him during a raid on their desert camp, the person said.

Since Salman ascended to the throne in 2015, his now 34-year-old son, commonly known as MBS, has consolidated power with an unprecedented offensive against potential opponents in the family, arresting other princes and removing them from key posts as he took control of ministries and major institutions.