Dagger from Oman or Yemen ?

[TVV]

Robin has identified this correctly, it is an Omani so called "royal" khanjar, though this style is reportedly worn by all members of society and not exclusively reserved for the royal family. Your is relatively modern, and I had a very similar one, and I still have an antique one as well. I do not have a picture of the two next to each other, but when looking at pictures of the details of the silver work on the hilt, the differences are clear to see.
While not of the same quality as older work, it is still a nice khanjar and a nice addition to a collection. But be careful, these khanjars (jambiyas) from Southern Arabia can get very addictive.