At least 140 people were dead and more than 800 others injured after weekend violence in China's far west Xinjiang region, the regional public security department said Monday, according to state-run media. The death toll was expected to climb, according to a regional government spokesman, as reported by China's official Xinhua news agency. Ethnic Uyghur residents in Urumqi, capital of Xinjiang, took to the streets Sunday afternoon in a rare public protest that prompted a police lock-down of the city, according to a report of CNN. By Monday, police had arrested several hundred participants, the Xinjiang Public Security Department said, according to Xinhua. Police were searching for about 90 other key figures. "Traffic control was partially lifted Monday morning in parts of Urumqi ... but tension still exists in the city," Xinhua said. "Debris has been cleared from the roads and normal traffic has resumed. Workers are still pulling away damaged vehicles from the worst-affected roads in the city." Most businesses in the area where the violence took place remained closed on Monday, Xinhua said.