Tens of thousands of troops have been deployed in the capital of China’s Xinjiang province, Urumqi, as security forces mounted a show of strength after recent ethnic violence. Wednesday brought an uneasy calm after several days of rioting.More than 150 people have been killed and many more injured in the clashes between the region’s Muslim Uighur population and Han Chinese. Troops used tear gas to break up protests and made more than 1,400 arrests. The violence followed years of tension as many Uighurs felt threatened by an influx of Han Chinese migrants from the east. On Tuesday Han protesters took to the streets with weapons seeking revenge for Sunday’s trouble. Shops and stalls belonging to Uighurs were smashed. President Hu Jintao was meant to be at the G8 summit in Italy but has flown back to China to deal with the problem. The Chinese authorities blame Uighur leaders at home and abroad who want an independent state.