Urumqi (China), Aug 4 (Xinhua) Chinese authorities Tuesday formally arrested 83 people in connection with the July 5 riots that left 197 people dead and more than 1,600 injured in the country's northwestern Xinjiang Uygur Autonomous Region, officials said.

Prosecutor Utiku'er Abudrehman made the announcement at a press conference in Urumqi, the capital of Xinjiang Uygur Autonomous Region.

The accused will face different charges, including murder, injury, arson and robbery, he said.

Speaking at the conference, Urumqi city police chief Chen Zhuangwei said 718 people are still being held for investigation into the riots.

He said the police have examined scores of crime scenes and interviewed over 1,000 people, including the relatives of those killed and injured in the riot.

The police also inspected shops and motor vehicles damaged in the violence and collected photos and video clips and other evidences of the crime scenes.