Security is on heightened alert and riot police on standby in China's western province of Xinjiang after a deadly blast.<br /> <br />Three people were killed and 79 were injured when attackers used knives and detonated explosives at Urumqi's south railway station.<br /> <br />The explosion was centred around this luggage abandoned near the station exit.<br /> <br />It's the second time this railway station has been targetted in two months.<br /> <br />Beijing blames this violence on separatists from the mainly Muslim Uighur minority.<br /> <br />The explosion happened as China's President Xi Jinping was wrapping up a tour of the region.<br /> <br />During his trip he stressed the need for tough policing to fight "terrorists".<br /> <br />The spokesman for the World Uighur congress said the government would now have carte blanche to arrest and repress many innocent Uighurs.<br /> <br />(SOUNDBITE) (Mandarin) SPOKESMAN FOR WORLD UYGHUR CONGRESS, DILXAT RAXIT SAYING:<br /> <br />"When Xi Jinping went there, he didn't do anything to ease the
