POG airport security, or not

I've just realized, and apaprently never paid attention prior to this, that there is absolutely nos security screening done at the Port Gentil airport. Of course, there is screening in Libreville, but Port Gentil is a bit more, um, relaxed of an operation. Also, for whatever reason, even on a domestic flight from Port Gentil to Libreville, they do a passport check upon landing. I suspect the two are not entirely unrelated.