SCENARIOS - Tension in China's restive Xinjiang

By Ben Blanchard

SHANGHAI (Reuters) - Chinese President Hu Jintao abandoned plans to attend a G8 summit in Italy on Wednesday, returning home early to deal with ethnic violence that has left at least 156 dead in China's northwestern region of Xinjiang.

More than 1,000 people have been injured and 1,434 arrested in unrest between Han Chinese and Muslim Uighurs since Sunday in Urumqi, capital of the the energy-rich region which borders Central Asia and Pakistan.

Here are some scenarios at how current tensions may play out:

WILL UNREST SPREAD TO REST OF XINJIANG?

- Demonstrations and even rioting could break out in other parts of the vast region, especially in areas which are heavily populated by minority Muslim Uighurs. Urumqi, by contrast, has a very large Han Chinese population.

Chinese state media have already reported on protests in the old Silk Road city of Kashgar and exile groups say other cities have also been affected, though those reports are hard to verify.

- But after the violence in Urumqi, Chinese security forces will rush in reinforcements to all parts of Xinjiang to try to nip any new protests in the bud, making a repetition of Sunday's riots unlikely though not impossible.