Xinjiang used to be the Turkish Islamic Republic of Eastern Turkestan before it was invaded by Communist China in 1949.
China rules with oppression similar to that we see in Tibet. The Chinese wholeheartedly supported Bush's war on Terror and used it as a pretext to further subjugate the indigenous population.
As anotheoldgit has rightly pointed out, they are not tied down by the European Court of Human Rights, so executions are commonplace. Between 1997 - 1999, the Chinese executed 200 people in the province. This month it has rounded-up 10,000 locals, and executed 2 of them
When they fight back, they are labelled as terrorists by the despots in Beijing.
Most of the British press has reported this attack as being by Separatists, Rebels or Assailants, but The Sun used the far snappier, Muslim fanatics.