Saudi Arabia’s powerful Crown Prince Mohammed bin Salman (MBS) has detained three senior members of the kingdom’s royal family in an attempt to remove any potential rivals in his pursuit of the throne, people familiar with the matter have said. Prince Ahmed bin Abdulaziz, King Salman’s younger brother, and Prince Mohammed bin Nayef (MBN), the king’s nephew, were arrested early on Friday. The details of the charges could not be learned, but the two Saudi royals were accused of treason, the reports said. The two men, who had once been in line for the throne, are now under threat of lifetime imprisonment or execution, people familiar with the matter said. Saudi authorities also detained Nayef’s younger brother, Prince Nawaf bin Nayef. According to the reports, guards from the Saudi royal court arrived at the homes of the two men on Friday morning and took them into custody. Easing tight social strictures, such as opening cinemas and allowing pop concerts, has proved wildly popular among many in the kingdom’s large youth population. But the opening up has been accompanied by a severe crackdown on dissent and conservatives have quietly grumbled about the pace and extent of change. In 2017, MBS launched an anti-corruption crackdown, imprisoning princes and businessmen in the Ritz-Carlton hotel in Riyadh, and coercing them into handing over assets in a drive that the government claimed netted more than $100bn.