MADRID—The leader of a movement seeking independence from Morocco who is at the center of a diplomatic row between Rabat and Madrid has flown out of Spain to Algeria, his group said. Brahim Ghali was released from a hospital in northern Spain following more than six weeks of treatment after contracting COVID-19, according to a statement sent to The Associated Press by the self-declared Sahrawi Democratic Arab Republic, which is based in refugee camps in western Algeria. Ghali is the leader of the Polisario Front, an Algeria-backed pro-independence movement representing the local Sahrawi people of Africa’s Western Sahara, and of the Sahrawi Democratic Arab Republic. Morocco annexed Western Sahara in the 1970s after Spain’s colonial administration ended. The Polisario Front has long tried to end Moroccan rule over the region. Ghali departed hours after testifying Tuesday via videoconference in a Spanish investigation into allegations against him of torture, genocide, and …