Jordan has announced a sweeping ban on the Muslim Brotherhood that could include shutting down the country's largest opposition party, after accusing the Islamist group of planning attacks.
The Islamic Action Front, a political party linked to the regionwide Brotherhood, won the most seats in parliamentary elections held last year against the backdrop of mass protests against Isarel over its war with Hamas.
The monarchy banned the Muslim Brotherhood a decade ago but officially licenced a splinter group and continued to tolerate the Islamic Action Front while restricting some of its activities.
It was not immediately clear how far the latest ban would go.
Police surrounded and searched the Islamic Action Front's headquarters after Wednesday's announcement and seized several boxes of documents.
The Interior Ministry said the Muslim Brotherhood is now considered an illegal organisation and announced a ban on any political activities related to the group and the closure of its offices.
It said efforts to confiscate the group's assets would be accelerated.
"It has been proven that members of the group operate in the dark and engage in activities that could destabilise the country," the ministry said.
"Members of the dissolved Muslim Brotherhood have tampered with security and national unity and disrupted security and public order."
The ministry also said that a son of one of the group's leaders had joined others in trying to manufacture and test explosives to be used against security forces, without providing names or further details.
Last week, Jordan said it had arrested 16 people accused of manufacturing short-range missiles, possessing explosives and automatic weapons, concealing a ready-to-use missile, and illegally recruiting and training people.
The government said the accused belong to what it called "unlicensed groups," referring to the Muslim Brotherhood.
The Brotherhood denied the allegations and said it was committed to Jordan's security.
Wael Al-Saqqa, Secretary-General of the Islamic Action Front, distanced the party from the Muslim Brotherhood, saying it had "no relationship with any other organisational body, whatever it may be."
He insisted the party has acted according to the law.
"We always declare that we are committed to order, the law, and the provisions of the constitution," he said, adding that he was surprised by the security services' search of the group's headquarters.
Jordan is a close Western ally that has long been seen as a bastion of stability in the often volatile Middle East.
It borders Israel, the occupied West Bank, Syria, Jordan, Iraq and Saudi Arabia, and is hosting hundreds of thousands of refugees from multiple conflicts.
The Muslim Brotherhood was established in Egypt nearly a century ago and has branches across the world.
Its leaders say it renounced violence decades ago and seeks to set up Islamic rule through elections and other peaceful means.
Critics, including governments across the region, view it as a threat.