BEIJING - Several hundred people have been arrested over riots in China's restive Xinjiang region, state media reported Monday, as the official death toll from the violence reached 140.

"Police have arrested several hundred participants, including more than 10 key figures who fanned the unrest on Sunday," Xinhua news agency said, citing the Xinjiang Public Security Department.

Police were still searching for around 90 other people in Urumqi - the capital of Xinjiang - where the riots occurred, according to Xinhua.