From The Scotsman:
A major row has broken out between China and Russia over the location for joint military exercises.

According to the Kommersant daily newspaper, the Russian military had suggested the Xinjiang autonomous region of China, because of the area’s problem with Uigur separatists and its proximity to Central Asia, a focus for the international fight against terrorism.

However, Beijing flatly rejected the proposal, and instead suggested the Zhejiang province near Taiwan.

Exercises in this area, the newspaper noted in its report yesterday, “would look too provocative and trigger a strong reaction not only in Taiwan, but in the US and Japan, which recently included the island in their zone of common strategic interests.”

“Beijing is trying to use Russia as an additional lever of pressure on the disobedient island,” it said.

Beijing is presumably also mindful of the history of Russian influence in Xinjiang prior to the assumption of full PRC control (the warlord Sheng Shicai who ruled the province prior to the arrival of KMT nationalists during the 1930s operated under heavy Soviet patronage, and the Soviets invested in the area during the period of the second East Turkestan Republic in the late 40s), which might explain why they would be leery about inviting the Russians into what remains a sensitive area.