Violence has taken place in Urumqi, the capital of northwest China's Xinjiang Uygur Autonomous Region on Sunday. Sources from the regional government say the unrest has led to the death of a number of civilians and one armed police officer. Rioters took to the street of Urumqi on Sunday evening.

Rioters took to the street of Urumqi on Sunday evening. They gathered, marched and demonstrated, culminating in violent acts.

An initial investigation shows the violence was masterminded by the separatist group -- World Uyghur Congress. The group is led by Rebiya Kadeer, who is a former Chinese businesswoman.

The group has recently been instigating unrest via the Internet and by other means, calling on the rioters "to be braver" and "to do something big."

The Xinjiang regional government says terrorism, separatism and extremism are behind the violence.