Morocco and several Arab countries walked out of an Africa-Arab nations summit in Equatorial Guinea on Wednesday to protest the presence of a delegation from the Polisario Front, media reports said.

Morocco, which is a big investor in Africa, quit the fourth Africa-Arab World Summit, which focuses on economic cooperation, along with seven other Arab nations - Saudi Arabia, United Arab Emirates, Bahrain, Qatar, Oman, Jordan and Yemen -- and Somalia.

The Moroccan delegation took the decision to protest "the presence of the emblem of a puppet entity in the meeting rooms", the Moroccan foreign ministry said, quoted by the Moroccan news agency MAP.

Morocco maintains that Western Sahara, a former Spanish colony under its control, is an integral part of the kingdom, while the Polisario Front, which campaigns for the territory's independence, demands a referendum on self-determination.

The Moroccan delegation quit the one-day summit in Malabo as Rabat is attempting to rejoin the African Union which it left in 1984 -- when it was then called the Organisation of African Unity -- to protest the admission of the Sahrawi Arab Democratic Republic declared by the Polisario.

In 1991, the United Nations brokered a ceasefire between the two sides.

But a promised referendum to settle the status of the vast desert territory home to half a million people has yet to materialise.

"Morocco has partnerships with Central Africa, West Africa and Southern Africa. We cannot allow such a blow", said one commentator.