The area of production of this kind of TK regroups the Gbaya-Ngbaka, the Ngbandi, the Ngombe and the Mbanja.
The Ngbandi include the Sango and the Yakoma.
And the Mbanja are known to have excellent blacksmith who works for the Ngbandi and the Ngbaka.
And the Yakoma are known for their works (forging) for the Ngbaka.
Nothing is simple in Africa...
So Danny is right
the handle looks like a Yakoma one.
http://lulef.free.fr/html/yakoma.html
or Sango
http://lulef.free.fr/html/sango.html
And Freddy see the triangle engravings on the blade, a characteristic of the Ngbaka, and the dots of the Yakoma.
So it seems to be a good mix !
In fact I'm not convinced that it's a throwing knife, they never have a handle made of wood (fragile).
Luc