I think these are women of SanterÃa, also known as Regla de Ocha, La Regla Lucumà or Lukumi, “a religion of West African and Caribbean origin influenced by Roman Catholic Christianity.”
We were pretty sure we heard their drumming and chanting coming from the buildings although we never saw more than these women and a few others dressed similarly.
Interesting from Wiki (speaking of the African slaves brought to Cuba in earnest beginning in the mid 1500s)): “…in order to preserve their authentic ancestral and traditional beliefs, the Lukumi people had no choice but to disguise their orishas as Catholic saints. When the Roman Catholic slave owners observed Africans celebrating a Saint’s Day, they were generally unaware that the slaves were actually worshiping one of their sacred orishas. Due to this history, in Cuba today, the terms “saint” and “orisha” are sometimes used interchangeably.
“This historical ‘veil’ characterization of the relationship between Catholic saints and Cuban orisha is made all the more complicated by the fact that the vast majority of santeros in Cuba today also consider themselves to be Catholics, have been baptized, and often require initiates to be baptized as well.”