There has been renewed violence in China’s restive region of Xinjiang, with reports that two people have been shot dead by police.Despite a massive security presence, the flare-up shows the city of Urumqi remains volatile. Ethnic rioting there earlier this month left at least 180 people dead and more than 1,600 others injured. Two Uighurs were killed in the latest incident, according to authorities. It is claimed police opened fire to prevent them assaulting another man from the same ethnic group. But a conflicting, unofficial account says the Uighurs had, in fact, been trying to attack security forces. Ethnic tension remains high between Xinjiang’s native Uighurs, a largely Muslim people culturally tied to Central Asia and Turkey and Han Chinese, who form the majority of China’s population.