Three people were killed and 79 wounded in a bomb and knife attack at a train station in the far western region of China on Wednesday, state media said, as President Xi Jinping was wrapping up a visit to the area.

Xi promised "decisive actions" against the "terrorists" behind the attack in Xinjiang, a region beset for years by violence the government blames on Islamist militants and separatists seeking an independent state called East Turkestan.

Quoting police, Xinhua News Agency said "knife-wielding mobs slashed people" at an exit of the South Railway Station of Urumqi, capital of the Xinjiang region, and set off explosives.