Some historians have looked for possible connections between the Khazars and the lost tribes of Israel, but modern scholars generally consider them to be Turks who migrated from the East. Scholars in the former USSR considered the Khazars to be an indigenous people of the North Caucasus. Some scholars, such as D.M. Dunlop, considered the Khazars to be connected with Uyghur confederation tribe called He’san in Chinese sources from the 7th-century (Suishu, 84). However, the Khazar language appears to have been an Oghuric tongue, similar to that spoken by the early Bulgars. Therefore, a Hunnish origin has also been postulated. Since the Turkic peoples were never ethnically homogenous, these ideas need not be deemed mutually exclusive. It is likely that the Khazar nation was made up of tribes from various ethnic backgrounds, as steppe nations traditionally absorbed those they conquered. 
But where are the Uighurs? they mainly live in Xinjiang.
This is how Uighurs look like
And this is how Jews look like
This is the Israel
But where is the Uighursrael?