(Washington Post) - Jordanian authorities detained the kingdom's former crown prince and arrested nearly 20 other people Saturday after what officials called a "threat to the country's stability."


Prince Hamzah bin Hussein, the oldest son of the late King Hussein and his U.S.-born wife Queen Noor, was placed under restriction at his Amman palace, amid an ongoing investigation into an alleged plot to unseat his half brother, King Abdullah II, according to a senior Middle East intelligence official briefed on the events.


The move followed the discovery of what palace officials described as a complex and far-reaching plot that including at least one other Jordanian royal as well as tribal leaders and members of the country's security establishment.


Additional arrests were expected, said the intelligence official, who like others interviewed, spoke on the condition of anonymity, citing security sensitivities surrounding the ongoing law-enforcement operation. A Jordanian adviser to the palace confirmed that arrests had been made related to a "threat to the country's stability."


Prince Hamzah served as Jordan's crown prince for four years before the title was transferred to the current monarch's eldest son, Hussein.


Hamzah was informed of his detention by senior Jordanian military officers who arrived at his house with an escort of guards, even as the other arrests were getting underway, the intelligence official said.


The sweeping arrests also have been reported on Jordanian social media.


It was unclear how close the alleged plotters were to carrying out the plan, or what, exactly, they planned to do. The intelligence official described the plan as "well-organized" and said the plotters appeared to have "foreign ties," though he did not elaborate.


Among the others arrested was Sharif Hasan, who also is a member of the royal family; and Bassem Awadullah, a Saudi citizen, the official said.


Jordan, a close ally to the United States, has been hard-hit economically by the covid-19 pandemic as well as the fallout from massive waves of refugees from Syria, its northern neighbor. King Abdullah has ruled the country since King Hussein's death in 1999, and cultivated close ties with a succession of U.S. Presidents. The resource-poor kingdom of 10 million is a major partner in the U.S.-led campaign against the Islamic State and has assisted U.S. forces in security operations around the globe.