Saudi authorities have detained three royal family members including two senior princes, the US media reported Friday, signalling the powerful crown prince is further tightening his grip on power.

Prince Ahmed bin Abdulaziz al-Saud, a brother of King Salman, and the monarch’s nephew Prince Mohammed bin Nayef were taken from their homes early Friday by royal guards after being accused of treason, the Wall Street Journal reported citing unnamed sources.

The detentions mark the latest crackdown by de facto ruler Crown Prince Mohammed bin Salman, who has consolidated his grip on power with the imprisonment of prominent clerics and activists as well as princes and business elites.

Prince Mohammed, the king’s son, has also faced a torrent of international condemnation over the murder of critic Jamal Khashoggi inside the kingdom’s Istanbul consulate in October 2018.

At the time, Saudi television channels showed Prince Mohammed kissing the hand of the older prince and kneeling before him in a show of reverence.

Western media reports later said that the deposed prince had been placed under house arrest, a claim strongly denied by Saudi authorities.

“Prince Mohammed is emboldened — he has already ousted any threats to his rise and jailed or murdered critics of his regime without any repercussion,” Becca Wasser, a policy analyst at the US-based RAND Corporation, said of the latest crackdown.