A couple of years ago, I blogged about a group of Palestinian Arabs I encountered in the Galilee who were obviously of African descent. I've stumbled across an academic article (original source unclear) published since then that discusses the history of some of the Palestinians whose recent ancestors were from Africa:
Most contemporary members of the African community came to Jerusalem as pilgrims and workers under the British Mandate of Palestine (1917-1948). They came mostly from Senegal, Chad, Nigeria and Sudan. They regard themselves as Palestinian and played an active role in the Intifada. Some of the Africans arrived as part of the Egyptian led 'Salvation Army' which aimed to liberate the Palestinian areas held by Jews in 1948. After the defeat of that army and its retreat to Egypt many Africans returned to their original countries, while others preferred to stay in Palestine.