The recent syringe attacks in Urumqi are being called "terror attacks" by regional officials.
"They aimed to unsettle the city's atmosphere," said Yan Yuxing, former president of Urumqi Municipal Intermediate People's Court.
The attacks, which targeted innocent people in the capital of northwest China's Xinjiang Uygur autonomous region, were not practical jokes or simple crimes perpetrated by one individual but organized and planned stabbings that disturbed the social order and created an atmosphere of fear, said Du Xintao, an official with the regional Public Security Department.
Local authorities said late on Tuesday another four suspects involved in the syringe attacks were prosecuted on Monday, bringing the number prosecuted to eight. Police have caught 45 suspects during the scare.
Du said they were not ordinary crimes but crimes against society.
To tackle the crisis, the government has posted guards in public places like buses, schools and hospitals.
The health department is treating victims. No deaths have been reported, nor have there been any cases needing anti-viral drugs, said an official with the regional center of disease control and prevention.
The government also held several press conferences and published several public notices since Sept 2 informing the public about the attacks and promising to punish the attackers.