Yes, you maybe in the published FIR/UFIR which cover many sovereign territories, but the O/F permission is for the Sovereign Territories. Check your charts for West Africa, and compare the FIR/UFIR boundries with those boundries of the Sovereign Territories.
Also if over water, BOM FIR is an example, you do not need a permit to transit the FIR if you are not within it's declared territory, ie the 'off coast' territorial waters, in that case a FPL will suffice (or should do) so ensure that the FIR centre is copied on the FPL at filing.