 The Moroccans are the world's longest-serving POWs |
The International Red Cross has urged the independence movement for Western Sahara, the Polisario Front, to release the remaining prisoners it holds. The agency said it remained "acutely concerned" for the physical and mental health of the detainees.
The Polisario Front has already freed hundreds of detainees this year, but is still holding 614.
The movement has accepted a United Nations plan for the former Spanish colony, which Morocco annexed in 1975.
Under the plan, Western Sahara would be granted limited autonomy followed later by a referendum on independence from, or integration with, Morocco.
 | The ICRC appeals for [the prisoners] to be released without delay, in accordance with international humanitarian law  |
The Moroccans reject the plan. Earlier this month, a delegation from the International Committee of the Red Cross visited some prisoners held by the Polisario and handed out blankets and medical supplies.
Almost 200 of the Moroccans still in captivity have been held for more than 20 years, according to the ICRC.
International efforts to bring peace in the region have foundered - principally over the fate of more than 100,000 refugees living in Polisario camps in Algeria.