He allowed those who wanted to surrender to leave.
Also, he had his white flag out meaning he won't kill those who left. If it was red, it meant if captured or surrendered he would kill them.
There are only three groups and these groups that conquered North Africa at one time or the other are the Romans, Muslim Arabs, and the Phoenicians. These groups have developed colonies in North Africa. One example is the Phoenicians who built colonies to the Atlantic from the Tripoli. Also, during the conquest of the Muslim Arabs, this started the spread of Islam all over the country.
More than five hundred separate languages are spoken in Nigeria alone. Three of the six dominant languages in Subsaharan Africa—spoken by at least ten million people or more—are spoken in Nigeria: Hausa, Yoruba, and Ibo. The three remaining major languages of Subsaharan Africa are Swahili, Lingala, and Zulu
