How many Spanish troops were killed during the retreat from Annual?

During the retreat from the frontline post of Annual (Anwal) in July 1921, Spanish forces suffered between 8,000 and 10,000 deaths. This rout, which followed the decision by Gen. Manuel Fernández Silvestre to abandon the position, resulted in the loss of all territory Spain had occupied in the eastern part of the protectorate since 1909.12