It is clear that the masonry unit is concrete block, but the type of block is unknown. The blocks may be hidden, or it may not be possible to determine solid from hollow blockwork, or information about it is unavailable.

CBH_Peru_Brzev_1

Various types of concrete blocks, Peru (S. Brzev)

CB99_Cuba_Brzev_1

Concrete block construction, Cuba (S. Brzev)