Domestically, Hamzah's unprecedented criticism of the ruling class - without naming the king - could lend support to growing complaints about poor governance and human rights abuses in Jordan.

Prince Faisal rejected claims by exiled former Saudi official Saad al-Jabri that the kingdom had sent a hit squad to kidnap or kill him, dismissing an attempt to "muddy the waters" and "distract from the fact that he has absconded with several billion dollars of Saudi government money".

He denied being part of "any conspiracy or nefarious organisation", but said the country of 10 million people had "become stymied in corruption, in nepotism and in misrule" and that no one was allowed to criticise the authorities.

"The investigations had monitored interferences and communications with foreign parties over the right timing to destabilise Jordan", Safadi said.

State-run news agency Petra said among those arrested for "security reasons" were former close aides to the royal family Bassem Awadallah, chief of the royal court in 2007-2008, and Sherif Hassan bin Zaid.

"We confirm here that there is now full control over these movements ... and the state services were able to smother them before they began", Safadi said.

The widow of Jordan's late king defended her son, Prince Hamzah, against allegations by the authorities that he carried out actions targeting "security and stability" in the kingdom.

On Twitter, Hamza's mother, Queen Noor called the incidents a "wicked slander".

Iraqi Prime Minister Mustafa Al Kadhimi called King Abdullah on Monday and reaffirmed his country's support for the kingdom.

Jordan in security sweep, king`s half-brother put under house arrest
The country's powerful intelligence agency has gained extra powers since the pandemic began, drawing criticism from rights groups. The move is thought to follow a visit by the prince to tribal leaders, where he is said to have garnered some support.

Labib Kamhawi, a Jordanian analyst, told the Associated Press that Hamzah likely crossed a line for the royal family by indicating he might be an alternative to the long-ruling king.

The sibling, former Crown Prince Hamza Bin Hussein, worked in concert with foreign entities, Deputy Prime Minister Ayman Safadi said on Sunday, in a first official explanation of a string of arrests a day earlier.

Washington and major Gulf powers were quick to pledge their support for King Abdullah and for all steps taken to ensure stability amid reports of a foiled coup plot.

In his phone call today with King Abdullah II, King Mohammed VI reassured him of Morocco's full support for the stability and security of Jordan. "All the solidarity with the Jordanian leadership and King Abdullah in defending the gains of the Jordanian people, protecting their stability, and refusing interference in their affairs". In 2004, however, King Abdullah II replaced Prince Hamzah and later designated his eldest son as the Crown Prince of Jordan.

Stability in Jordan and the status of the king have always been a concern throughout the region, particularly during the Trump administration, which gave unprecedented support to Israel and sought to isolate the Palestinians, including by slashing funding for Palestinian refugees.

The leaders also voiced support for all measures and decisions taken by Jordan to safeguard its security and stability, according to a Royal Court statement.

It said strategic bilateral relations "will remain an honest and strong guard against any attempts to undermine the security and stability in the two countries and the region". In the night from Saturday to Sunday, Hamzah had announced in a secretly recorded video leaked to the media that he had been placed under house arrest.

"Palestinian President Mahmoud Abbas said that we stand by the sisterly Hashemite Kingdom of Jordan, the king, the government, and the people", official Palestinian news agency WAFA said in a statement. He also attended Harvard University in the United States and has served in the Jordanian armed forces. "We need to do everything necessary to maintain that alliance".

"Ahmed Aboul Gheit added that King Abdullah II has a high and appreciated position, whether among the Jordanian people or on the Arab level in general, and that everyone knows his sincerity and his great role in serving Arab causes".