A court in China's western Xinjiang region has sentenced four men to prison terms of eight to 15 years for allegedly jabbing a pedestrian with a hypodermic needle.
State media say a court in the regional capital of Urumqi issued the verdicts.
The sentences bring to seven the number of people convicted over the mysterious syringe attacks. All are members of China's Uighur ethnic group.
Authorities have moved swiftly to hand out the sentences as part of an apparent effort to calm the public.
The reported hundreds of attacks raised public anxiety in Xinjiang at a time when the region was already on edge.
Ethnic riots broke out in Xinjiang in early July between Han Chinese and Uighurs - a Muslim ethnic group native to Xinjiang. According to officials, the unrest left nearly 200 people dead - mostly Han Chinese - and more than 1,700 injured.China's public security minister has called the attacks an organized terror, claiming it was organized by the same Muslim separatists behind the region's unrest in July. No evidence has been shown to back up the government's claim.
Although there have been reports of hundreds of attacks, authorities say only a few dozen people have shown definite signs of having actually been jabbed with hypodermic needles. Instruments used in attacks have reportedly also included safety pins and even tooth picks, and no serious injuries have been reported.
Xinjiang was hit by violence in early July when police cracked down on a group of Uighurs gathered to protest the deaths of two Uighurs at a factory in southern China. Uighurs then attacked Han, prompting revenge attacks two days later.