Saudi authorities on Friday have detained three royal family members including two senior princes, the US media reported, 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.

Prince Nayef's younger brother Prince Nawaf bin Nayef had also been detained. Saudi authorities did not immediately respond to requests for comment, The New York Times reported

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 Ahmed, said to be in his 70s, had returned to the kingdom from his base in London in the aftermath of the Khashoggi scandal, in what some saw as an effort to shore up support for the monarchy.

In June 2017, Prince Mohammed had edged out Prince Nayef, the former crown prince and interior minister, to become heir to the Arab world's most powerful throne.

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.

"This is a further step to shore up his power and a message to anyone — including royals — not to cross him."

The detentions come at a sensitive time as Saudi Arabia bars Muslim pilgrims from Islam's holiest sites to contain the novel coronavirus.

The kingdom has suspended the "umrah" year-round pilgrimage over fears of the disease spreading to Mecca and Medina, raising uncertainty over the upcoming hajj —a key pillar of Islam.

The oil-rich kingdom is also grappling with plunging price of crude, its major source of revenue.