Can't see the coins too well, but clearly Spanish or (more likely) Spanish-American, minor denominations. These would most likely have circulated in Spanish America, not the Orient as did large (8 Reale) silver, nor in Africa. So, I'd say, unlikely African.
Fairly certain that this necklace is from Ecuador.
I have 4 similar examples - one with coral beads, one with coral tubular white hearts and one with deep red glass beads, and one that's just brass. All the brass beads are very similar and just like your picture.
Some of my examples have brass crucifixes. All have a few coins (from 1700's to 1928) - from Ecuador, Chile, Colombia and Peru.
I bought two of the necklaces in Ecuador in 1978. More recently, during a trip to Otavalo Ecuador, I was told the brass used to be made locally but no longer.
I'll try to post pictures later, if I can figure out how to do it.