Huneiti said that Prince Hamzah was asked to "cease any movement and activities that could be used to target the security and stability of Jordan " and that "a comprehensive joint investigations carried out by the security services led to the arrests of Sharif Hassan Bin Zaid and Bassan Awadallah and others", Petra reported.
The news agency reported earlier on Saturday that Jordanian security forces had arrested a former adviser to King Abdullah and others on "security related" grounds.
Almost 20 arrests were made, and an intelligence official said more would follow.
"We are closely following the reports and in touch with Jordanian officials", said US State Department spokesman Ned Price.
After the arrests, the Saudi royal court expressed full support for King Abdullah, as well as Egypt, Lebanon and Bahrain.
According to the BBC, the move to detain Hamza came after he met with tribal leaders and reportedly garnered their support.
King Abdullah II backed by Jordan's powerful Gulf allies after several senior figures were detained.
"There were efforts that threatened Jordan's security and stability and these efforts were foiled", the minister said.
He said that Jordan's crackdown on any sort of criticism has stoked fear in the country.
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".
Jordan's king places half-brother under house arrest after public criticism
Huneiti affirmed that "no one is above the law and that Jordan's security and stability take precedence over any consideration". Majali's niece, Basma, wrote on Twitter that their family house was raided and Majali was taken to an unknown destination.
Most politicians believe Prince Hamza will be silenced and unlikely to pose a threat, given that the armed and security forces strongly support King Abdullah.
On Saturday the military said it had issued a warning to the prince over actions targeting "security and stability" in the key USA ally. Any astute observer will say if someone this close to MBS is involved he would have to know, said the former US official.
"The investigations had monitored interferences and communications with foreign parties over the right timing to destabilise Jordan", Safadi said. He commands a loyal following in Amman and, with his trim mustache and checkered keffiyeh headdress, often styles himself after his father, the late King Hussein, a revered figure in Jordan.
At the same time, the king's tough reaction - placing his popular half-brother under house arrest and accusing him of serious crimes - illustrated the limits on public dissent he is willing to tolerate.
"But at the end, the security and stability of Jordan are above all consideration and all the necessary legal procedures will be taken to protect them", Safadi said.
King Abdullah removed Prince Hamza from his position as heir to the throne in 2004, in a move that consolidated his power.
The secretary general of the Arab League, in a statement posted on Facebook, said the organization "expressed full solidarity" with the measures taken to maintain security and stability.
Before becoming royal court chief in 2007, he was head of the king's cabinet in 2006.
Saturday's security sweep comes as Jordan prepares to mark 100 years since the new kingdom then named Transjordan was established alongside Palestine under British mandate.
It declared independence in 1946, and despite having little oil wealth, severely lacking water and repeatedly being rocked by wars on its borders, the kingdom has managed to survive the regional upheavals.