Trucks carrying hundreds of Chinese troops roll through the centre of Urumqi.<br /> <br />Security has been heightened and police are on alert, just days after one of the country's deadliest attacks in the troubled Xinjiang province.<br /> <br />Chinese state television announced on Saturday that the authorities have launched a one-year crackdown to hunt down and punish militants in Xinjiang.<br /> <br />It comes after thirty nine people died and 90 were wounded on Thursday when two vehicles drove into crowds at a market in Urumqi and threw explosives.<br /> <br />In a show of force, China's Minister of Public Security spoke to hundreds of troops and police nearby, inspecting officers on the streets.<br /> <br />He also attended a ceremony commemorating the victims of Thursday's suicide attack.<br /> <br />Police say they have identified the five suspects. They all appear to be Uighur.<br /> <br />Xinjiang, which is home to the Muslim Uighur minority has seen a spate of attacks in recent years.<br /> <br />Beijing has blamed these
