These staffs are definitely Southern or South East African. I've seen a few over the years.
My gut tells me I saw one of these in Situ amongst the Barotse (Lozi) tribe in the early nineties, but I was not taking photographs at the time and can not be sure.
I would think that these staffs are probably ceremonial in nature rather than throwing clubs due to the lack of damage or wear from throwing use that I've seen on any of them.
I've attached two pictures of similar staffs to this post. The first is from the Royal Museum for Central Africa in Belgium, where it's attributed to the Shona:
http://www.africamuseum.be/collectio...objectid=55811
The second one was being sold last year by Wallis & Wallis auction house in the UK, and was attributed as a Southern African knobkerrie.