A Muslim Wolof, Abdul Injai initially came to notice while assisting in the punitive military missions of Portuguese colonialists Oliveira Musanty and Teixeira Pinto, from 1905 to 1915.
Tenuous alliances, like those between Abdul Injai and the Portuguese during the Scramble for Africa, reflect the overwhelming tendency for European colonial powers to attempt to divide native African populations based on religious affiliations - particularly the idea that, although racially inferior to Europeans, Muslim Africans possessed higher levels of education and culture and were preferential associates compared to followers of animist or tribal religions.
An outraged Portuguese lawyer later published a damning report on the atrocities committed by African mercenaries under the command of Abdul Injai and Pinto:"Numerous bands, in which were also found the old, the crippled, women and children, fled, terrorized in the face of the triumphant march of the force of the irregulars [the mercenaries].
And in the disorderly flight, numerous natives, men, women, old people, children and the crippled, perished, drowned in the river, and ... mercilessly killed by the same irregulars.
From August 1-2, colonial forces engaged with the mercenary army, and after losing most of his soldiers, Abdul Injai surrendered to Portugal.