A series of attacks on police in the province around last month's Beijing Olympic Games left more than 20 officers and security guards dead, and at least as many attackers killed or arrested, in the biggest unrest there in years.

As the Muslim fasting month of Ramadan began, local governments this week issued orders to clamp down on security in the region and stop its ethnic Muslim Uighur population from using the holy month to foment further unrest.

"Faced with recent violent and disruptive activities by religious extremists, separatists and terrorists, we must... step up ideological education of religious leaders and followers," a notice posted on Xinjiang's Zhaosu county website said.

The county government prohibited government officials, Communist Party members, teachers and students from observing Ramadan, while warning that "any person caught forcing another to observe Ramadan" would be punished.