"We will be on high alert against those instigators. They are dreaming of splitting Xinjiang from our great motherland everyday," Nur Bekri, chairman of the regional government, told reporters.
Bekri, a Uygur who headed the provincial government for some time, vowed a resolute crackdown on separatism, terrorism and extremism in Xinjiang with an "iron fist."
"Terrorists do not stand for any ethnic group or any religion," he said, noting that people of all ethnic groups in Xinjiang strongly condemn any form of violence and terrorism.
His remarks came days after knife-wielding assailants killed 29 civilians and injured another 143 others at a railway station in the southwestern Chinese city of Kunming.
Bekri also defended China's ethnic policy, calling it the best in the world.
"Some people are always pointing their fingers at China's ethnic policy. They must have ulterior motives," he was quoted as saying by state-run Xinhua news agency.
Xinjiang borders several Central Asian States, besides Afghanistan and Pakistan-occupied Kashmir.
China had blamed al-Qaeda backed East Turkistan Islamic Movement for the attack.
