Jordan's Prince Hamzah, accused of plotting against his half-brother King Abdullah II, has struck a defiant tone, insisting he will not obey orders restricting his movement.

The government has accused Hamzah of involvement in a seditious conspiracy to "destabilise the kingdom's security", placed him under house arrest and detained at least 16 more people.

But 41-year-old Hamzah, who says he has been ordered to stay inside his Amman palace, vowed he would defy orders limiting his freedom of movement.

"I don't want to make moves and escalate now, but of course I'm not going to obey when they say you can't go out, you can't tweet, you can't communicate with people, you're only allowed to see your family," he said in an audio recording posted on Twitter late Sunday.

Hamzah -- a former crown prince stripped off that title by Abdullah in 2004 -- has emerged as a vocal critic of the monarchy, accusing it of corruption, nepotism and authoritarian rule.

In a video he sent to the BBC Saturday he denied being involved in a plot, and said he had been ordered under house arrest by Jordan's most senior military figure, General Youssef Huneiti.

In the latest recording, Hamzah said that: "When the head of the joint chiefs of staff comes and tells you this, it's a bit ... I think it's a bit unacceptable".

The palace turmoil has laid bare a rift in Jordan, usually considered a bulwark of stability in the Middle East.

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.