Saudi Arabia has reportedly detained three senior members of the Saudi royal family including Prince Ahmed bin Abdulaziz, a younger full brother of King Salman, and the monarch's nephew Prince Mohammed bin Nayef.

Prince Ahmed was one of only three people on the Allegiance Council, made up of the ruling family's senior members, who opposed Mohammed bin Salman becoming crown prince in 2017, sources have told Reuters.

The arrests were the latest move Riyadh has made to quash potential opposition to the crown prince and came after Riyadh closed off the holiest sites in Islam to foreign pilgrims over the coronavirus outbreak.

According to the Wall Street Journal, both Prince Ahmed bin Abdulaziz and Prince Mohammed bin Nayef, once potential contenders for the throne, were accused by the Saudi royal court of "plotting a coup to unseat the king and the crown prince." They were taken from their homes early Friday by black-clad royal guards.

In 2017, the crown prince locked up hundreds of royal relatives and wealthy businessmen in a Ritz-Carlton hotel, marking the first sign of his iron grip on the kingdom. 

Several smaller-scale arrests made on princes have also taken place in the past two years.

(Cover image: Saudi Crown Prince Mohammed bin Salman attends a session of the Shura Council in Riyadh, Saudi Arabia, November 19, 2018. /Reuters)

(With input from agencies)