One other person on board was lightly injured in the crash, a military source told MAP, adding that a "technical investigation" had been launched to determine the cause of the incident near the settlement of Tichla.

The Moroccan military has a heavy presence in the swathes of Western Sahara it controls.

It maintains that Western Sahara, a former Spanish colony under its control, is an integral part of its territory.

The Polisario Front, which campaigns for the territory's independence, demands a referendum on self-determination.

The Polisario Front liberation movement and Morocco fought a war over the region from 1975 to 1991, when a ceasefire deal was agreed and a UN peace mission deployed to monitor the truce in the former Spanish colony.