Dozens of prisoners at a detention center in southern Yemen controlled by the United Arab Emirates say they have started a hunger strike to protest their indefinite detention without charges or trials.

About 100 prisoners in the Beir Ahmed prison in the southern city of Aden say in a statement that was leaked to the media that their open-ended strike started on Monday and would continue until their demands are met.

They say Aden prosecutors have ordered more than 70 detainees released but the prison's Emirati commanders refuse to let them go.

The detainees, before they were transferred to Beir Ahmed, were among hundreds rounded up on terror charges and held in secret UAE-run detention centers in southern Yemen where prisoners were reportedly tortured. The UAE has denied the allegations.