I found this information useful, they have different religions and ethnicities in Xinjiang, and most are Muslims.

http://www.china.org.cn/english/MATERIAL/139389.htm

It does not make sense that if China is attacking Muslims, why the other groups are not complaining.  It seems that the Uighur's are as a majority have a separatist movement going on.

It's unfortunate that so many are swayed into the idea of separatism when China has respected Islam throughout the dynasties including in Xinjiang.

So far I cannot find any evidence that backs up the claims of the Uighur's, only that even according to Amnesty International's admission, Rebiya Kadeer, the leader of foreign Uighur's was treated well until she was arrested on separatist charges.