SHANGHAI—Chinese police gunned down 59 people and arrested 215 during a violent uprising last week in the Xinjiang region, the government said Sunday, in a statement that shed fresh light on what dissident groups had earlier described as a major clash in the area.

In coordinated predawn actions on July 28, unnamed assailants attacked civilians, state buildings and vehicles in two Xinjiang towns, including Elixhu, according to police descriptions reported by the government-run Xinhua news agency.

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