Never saw a place for it, you may find in Najma market.

I sharpen my knives myself....I usually use stone or steel
Youtube was very helpful to learn how to use them

Sharpening Stone
http://www.youtube.com/watch?v=lBXRkMZfIXk

Sharpening Steel
http://www.youtube.com/watch?v=-Scktc0iSdM

Also you can get sharpener shown below in supermarkets, which is very easy to use
www.knife-depot.com/images/product/fb/215779.jpg

Cheers...