Jordan's King Abdullah broke his silence Wednesday to tell his nation that the worst political crisis in decades sparked by an alleged plot involving his half-brother Prince Hamzah was over.

The government had accused Hamzah -- a former crown prince who was sidelined as heir to the throne in 2004 -- of involvement in a conspiracy to "destabilise the kingdom's security" and arrested at least 16 people.

But Abdullah said Wednesday that Hamzah, who has signed a letter pledging his loyalty to the king following mediation by an uncle, was safe in his palace under his "care".

"I speak to you today, my family and my tribe... to assure you that the sedition has been nipped in the bud, and that our proud Jordan is safe and stable," Abdullah said in an address read out in his name on state television, a day after an official news blackout on the affair.

Map of Jordan
Map of Jordan AFP / STAFF

"The challenge over the past few days was not the most difficult or dangerous to the stability of our nation, but to me, it was the most painful," he said, according to an official English translation released after the broadcast.

"Sedition came from within and without our one house," he added.

In using the words "from within", it was not clear whether the king was referring to actors in the royal family or the wider kingdom.

Foreign Minister Ayman Safadi on Sunday charged that the plotters had linked up with foreign parties, but had declined to identify them.

Family tree of Jordan's late king Hussein, father of current king Abdullah II and former crown prince Hamzah bin Hussein.
Family tree of Jordan's late king Hussein, father of current king Abdullah II and former crown prince Hamzah bin Hussein. AFP / Gal ROMA

Reacting to the events, Abdullah said he felt "shock, pain and anger, as a brother and as the head of the Hashemite family, and as a leader of this proud people".

Hamzah was appointed crown prince in 1999 in line with his father's wishes, but Abdullah stripped him of the title in 2004 and named his eldest son in Hamzah's place.

After claiming he was put under house arrest Saturday, Hamzah had made extensive use of traditional and social media to lash out against his situation.

Women walk past a poster of Jordan's King Abdullah II on a street in the capital Amman on Tuesday
Women walk past a poster of Jordan's King Abdullah II on a street in the capital Amman on Tuesday AFP / Khalil MAZRAAWI

He accused Jordan's rulers of corruption and ineptitude in a video message published by the BBC on Saturday.

But after a statement voicing his loyalty to the king on Monday, Abdullah said Wednesday that Hamzah had offered his support for the monarchy.

"Hamzah today is with his family, at his palace, in my care," Abdullah said in his address.

"Prince Hamzah pledged before the family to follow in the steps of the ancestors, remain loyal to their mission, and to put Jordan's interest, constitution, and laws above all considerations."

A probe into the events continues, the king said.

People shop in Jordan's capital Amman on April 5; ordinary Jordanians say a reporting blackout on matters of the royal family mean they hear little news on the matter
People shop in Jordan's capital Amman on April 5; ordinary Jordanians say a reporting blackout on matters of the royal family mean they hear little news on the matter AFP / Khalil MAZRAAWI

"As for the other aspects, they are under investigation, in accordance with the law... in a manner that guarantees justice and transparency," he added.

The crisis had laid bare divisions in a pro-Western country usually seen as a bulwark of stability in the Middle East.

Jordan borders Israel and the occupied West Bank, Syria, Iraq and Saudi Arabia. It hosts US troops and is home to millions of exiled Palestinians and more than half a million Syrian refugees.

The ruling monarchy had said it was settling the matter "within the framework of the Hashemite family".

US President Joe Biden called Abdullah Wednesday to express his "strong support" for the monarch, and "underscore the importance of King Abdullah II's leadership to the United States and the region," the White House said in a statement.

Major Gulf powers, Russia, Egypt and the Arab League have all pledged support for Abdullah, and on Wednesday, European Commission chief Ursula von der Leyen visited Amman.

After meeting with Abdullah, she said the EU was "ready to continue its long-term partnership and contribute to prosperity and stability".

The king's address followed orders issued Tuesday by Amman prosecutor Hassan al-Abdallat that banned the publication of any information about the alleged plot in order to keep the security services' investigation secret.

Jordan's media was told to wait for official statements before publishing anything about those arrested.

Wednesday morning's newspapers were dominated by the visit the day before of Saudi Foreign Minister Faysal Bin Farhan with a message from King Salman, and by developments in the coronavirus outbreak ravaging the country.

Mustafa al-Riyalat, editor-in-chief of pro-government newspaper Addustour, said Jordanians "all feel reassured, because it's as if nothing happened."

In the streets, Jordanians voiced relief.

"When the crisis erupted on Saturday, there was no one in the streets. People were afraid," said Shady, 41, who owns a clothing store in the capital Amman.

"But thank God, it was resolved within the royal palace."

But Ahmed Awad, of the Phenix Center for Economics and Informatics Studies, warned that the crisis was not yet over.

"There was a solution within the royal family, but not a solution to the political crisis," he said.

"The real political crisis... will continue until there are more democratic reforms."