Some 200 Moroccan former prisoners of war from the conflict in the Western Sahara have begun a sit in outside parliament in Rabat, claiming compensation for their years in detention.

The protesters, some of whom were held for more than 20 years by the pro-independence Polisario Front, had camped out on a street next to the parliament building for months, but were ordered to leave at the weekend, the group's organiser said.

"The operation took place in the middle of the night (on Saturday-Sunday). They told us that any camping was forbidden," said Samir Abdallah, information confirmed by government sources.

In response, the former soldiers have staged the daytime sit-in since Monday, demanding better compensation for their sacrifices.

Abdallah says there are more than 2,000 ex-prisoners, some suffering from chronic illnesses, who were declared unfit when they were released -- between 1996 and 2005 -- and retired.

"The pensions have been calculated according to our rank at the time we were captured" in the 1970s and 1980s, said Abdallah, himself a former officer.

He says the pensioners get between 600 and 3,000 dirhams (55 to 270 euros) per month, even though "many of us married late, after being freed, and have children to support."

The protesters organised a sit-in last year that lasted two months, and a "partial agreement" was reached, with the authorities pledging to provide them with taxi licences and accommodation, Abdallah said. But these have yet to materialise.

An official in Rabat said the government was in the process of "closely studying" the former soldiers' demands.

Morocco annexed the Western Sahara in 1975, in a move never recognised by the international community.

The Polisario Front launched its struggle for independence even before the annexation. The resulting war lasted until 1991 when the UN brokered a ceasefire but a settlement of the conflict still remains elusive.