This has been going on for years.
The Xinjiang Uigur Autonomous Region adjoins a bunch of "Stans" and is primarily ethnically Turkic. It's a lot different than going to Beijing or Shenyang.
It's the freaking wild west out there. They blow up buses, trains, bicycles, mopeds, etc. It's 47% ethnic Uigur and 7% ethnic Kazak. Ethnic Chinese are a minority there. It borders Kazakhstan, Kyrgyzstan, Taijikistan, Afghanistan and Pakistan, as far as Stans go. It also borders Russia and India.
There's been a separatist movement for years there. The Uigurs are ethnically Turkic in nature, Muslim, and would much rather be their very own Stan rather than a part of China.
This region also includes the Gobi Desert and the place where the Chinese liked to do their underground nuclear testing.
It has about as much in common as Beijing as Mosul has in common with Dallas.
I HIGHLY doubt this is in any way related to any terrorism against the West. Anyone who's been paying attention to the region knows this is a regularly scheduled summer activity there. It's too damned cold in the winter there for anyone to try this outside of the summer months.