Continuing tension in China’s Xinjiang province has forced the country’s president to abandon this week’s G8 summit in Italy.In Xinjiang’s capital, Urumqi, government troops are enforcing a curfew to stop ethnic violence that has left at least 156 people dead since Sunday. An influx of Han Chinese workers from the east into Xinjiang in recent years has created friction with the region’s Muslim Uighur population. On Sunday tension erupted into violence, when groups of Uighur protestors vented their anger over what they say is repression of their culture. By Tuesday it was the Han who were on the streets with weapons, seeking revenge. Troops have intervened, using tear gas to break up protests and making more than 1,400 arrests. President Hu Jintao was meant to be in L’Aquila to meet G8 leaders on Thursday but has flown home to address the problem. Government officials have blamed the trouble on forces both at home and abroad who want an independent Uighur state.