Thousands of people descended on the streets of Madrid capital on Saturday to demand self-determination for Western Sahara.
The demonstration was the culmination of month-long marches to highlight the plight of the native Sahrawi people, thousands of whom have been displaced in refugee camps for decades.
Morocco annexed the area on the northwest coast of Africa, between Algeria and Mauritania, in the 1970s after Spain's colonial administration ended.
Morocco considers the vast territory part and parcel of the kingdom. It agreed to hold a referendum in conjunction with the UN on the future of the territory in 1988 but this has yet to take place.
The conflict was deepened last year when then-U.S. President Donald Trump agreed to recognise Morocco's sovereignty over the territory in exchange for normalisation of ties between Rabat and Israel.
Demonstrators in Madrid called for both Spain and Morocco to support the autonomy of the Sahrawi Arab Democratic Republic (SADR), a portion of Western Sahara controlled by resistance movement the Polisario Front.
Protester Mazah Kulti, who left her father behind in Western Sahara when she was two years old, accused Morocco of "illegally occupying, looting in a abusive way our resources and coercing the population."
Meanwhile fellow protester Minechu Embarek explained Sahrawis were attending the demonstration as people "who doesn't have a land, doesn't have anything".
Tensions have risen between Madrid and Rabat after Brahim Ghali, the 71-year-old president of the SADR, came to Spain in April for hospital treatment for COVID-19.
Morocco retaliated by a relaxation of migration controls, leading to more than 6,500 would-be migrants flooding to the Spanish island of Ceuta in a matter of months.
Spain also recently withdrew from the annual US-led "African Lion" military drills, which involved more than 7,000 American, African, European and NATO troops and were held this year in Western Sahara.