Islamist cleric Abu Qatada, on trial in Jordan on terrorism charges, and dozens of other Islamist inmates have stopped accepting meals in protest at the conditions in jail.
"Around 120 Islamist prisoners in four jails in the kingdom have stopped accepting meals provided by the government," police spokesman Major Amer Sartawi told AFP.
"They claim that they are doing that to protest against prison conditions. They are buying food from canteens at prisons. They are in good health."
One of Abu Qatada's brothers confirmed, without elaborating, that the prisoners began their protest on Saturday.
The prisoners include Abu Muhammad al-Maqdisi, a jihadist ideologue and former mentor of Abu Musab al-Zarqawi, the slain leader of Al-Qaeda in Iraq.
"The inmates are demanding that authorities allow them more time outside their cells and more time with their families. They also want to get their own books," a security official told AFP.
Britain expelled Abu Qatada last summer after Amman and London ratified a treaty guaranteeing that evidence obtained by torture would not be used in his retrial and that the proceedings would be transparent.
Palestinian-born preacher Abu Qatada was condemned to death in absentia in 1999 for conspiracy to carry out terror attacks, including on the American school in Amman.
However, the sentence was immediately commuted to life imprisonment with hard labour.
In 2000, he was sentenced in absentia to 15 years for plotting to attack tourists in Jordan during millennium celebrations, and videotapes of his sermons were allegedly found in the Hamburg flat of 9/11 ringleader Mohammed Atta.
Abu Qatada has pleaded not guilty to all charges.
If convicted, he could face a minimum of 15 years' hard labour.