The attacks come less than two months after riots in the city in which 197 people were killed and 1,600 injured.

Zhu Hailun, head of the political and legal affairs commission of the Communist Party of China (CPC) committee in Xinjiang, said members of nine ethnic groups, including the Han, Uighur, Hui, Kazak and Mongolian, had reported stabbing incidents to the police in recent days.

Police have seized 15 suspects for attacking people with hypodermic needles in Urumqi, said Zhu.