China on Thursday blamed "extremism, separatism and terrorism" for the unrest in Xinjiang that has left more than 150 people dead and over 1,000 injured.
President Hu Jintao convened a meeting of the country's top leaders on Wednesday to discuss the situation in Xinjiang which erupted on Sunday when members of the mainly Muslim Uighur minority clashed with the majority Han Chinese.
"The incident in Urumqi (Xinjiang's capital) on July 5... is a serious violent criminal event instigated and organised by the three forces from abroad and at home," said a statement from the meeting published by state media on Thursday.
At a regular briefing on Thursday, Chinese foreign ministry spokesman Qin Gang identified these three forces as "extremism, separatism and terrorism".
However, neither the leadership nor Qin gave details of any specific groups behind the unrest, nor did they provide evidence to back their assertions. Qin however called on the international community to unite against the threat.
"As for some separatist activists in China, who are members of the three forces, we have evidence that shows that these people have received training abroad, including training from the Al-Qaeda organisation," he said.
"So in cracking down on these three forces, the international community should unite as one, and take actions as one, strengthen cooperation in this regard instead of taking double standards."
Xinjiang, a vast area that borders Afghanistan and Pakistan, has about eight million Turkic-speaking Uighurs, many of whom say they have for decades suffered Chinese political and religious persecution.
China says it faces a serious terrorist threat from Muslim separatists in Xinjiang, but rights groups have accused Beijing of exaggerating the threat in order to justify very tight controls in the region.
The government has said the East Turkestan Islamic Movement, listed by China and the United Nations as a terrorist organisation, was responsible for deadly attacks in Xinjiang in the lead up to last year's Beijing Olympics.