silver mounted file knife

[kahnjar1]

As has been suggested by others here, I would also say Arabian, and probably a Shafra. As suggested by Emmanuel, this type of knife is often worn as a "back knife" to the Khanjar/Jambiya, but this one is bigger than those of I seen worn in this way. Similar to the Shafra in shape, is the 19th century Al Mahri Khanjar, from the Al Marah region of southern Arabia. Size of this item is approx same as the one in this post.
Regards Stuart