Literally children of the landowner. The families, and the young men acting for them, who claim customary ownership of a piece of land.
The problem is not that customary ownership is fictitious — the Land Use Act 1978 vested land in the Governor, but families held it before that and the claims did not evaporate. The problem is that the claim is not exhaustive: pay one group and another appears, and each stage of building attracts a fresh levy.
This is a risk for anyone buying land or building. It matters much less for renting an existing flat, but a landlord whose own title is contested is a landlord who may lose the property.