BEIJING  - Eleven people died in bombings and fierce clashes between police and attackers in China's remote northwest Sunday, state media reported, the second outbreak of deadly violence there in under a week. Soldiers were called in to secure the city of Kuqa in Xinjiang, a Muslim-populated region home to what China says are terrorists intent on turning the nation's Olympic celebrations into mourning. Chinese authorities did not identify who the attackers were in the assault, but said they targeted police and government offices, supermarkets and hotels, and that some of them killed themselves when confronted by security forces. Ten of the attackers died in the violence, while one security guard was killed, the official Xinhua news agency reported. The clashes began with assailants setting off an explosion at Kuqa police station, with that blast killing the security guard as well as injuring two policemen and two civilians, according to Xinhua. Police shot eight of the "bombers" dead and two of them "blew themselves up," Xinhua reported without elaborating. There were at least 15 attackers involved in the day's violence in total, and 12 gas-based pipe bombs exploded in all, it said. Police had arrested two of the assailants, and were searching for three others, Xinhua said. Dozens of unexploded devices were seized, it added. Local authorities refused to comment when contacted by AFP, but a resident confirmed Xinhua's report that the military and police had quickly locked down the centre of Kuqa, a city of 400,000 people. "Don't come today, the town centre is closed," a receptionist at the Kuqa Hotel told AFP by phone. It was the second deadly assault in less than a week in Xinjiang, a vast area that borders central Asia.