BEIJING , China ( CNN ) -- Thousands of Chinese demonstrators crowded the streets of Urumqi in western China on Thursday to protest what they say is a lack of police protection , witnesses said . Chinese soldiers have been recently deployed on the streets of Urumqi in northwest China . Over the past month , more than 400 ethnic majority Han Chinese have been stabbed with tainted syringes by Uyghurs , the Muslim minority , according to local news reports . The stabbings fueled Thursday 's protests by Han Chinese in the capital of China 's Xinjiang Uyghur Autonomous Region . Many of those attacked with the hypodermic needles were hospitalized , but there have been no reports of deaths , the reports said . Fifteen suspects have been detained for allegedly carrying out the stabbings , a senior official said Wednesday , according to China 's state-run Xinhua news agency . Of the 15 , four have been formally charged , Xinhua reported . A source told CNN that `` countless '' police and soldiers have deployed to Urumqi and so far , the demonstrations have been peaceful . A local woman told CNN that the stabbings were ethnically motivated and that government text messages to citizens have warned that the syringes contained an unknown disease . Ethnic-fueled violence between the Han Chinese and Uyghurs has plagued Urumqi since July , when soldiers and police stormed the streets to quell riots . Unconfirmed reports of deaths in those riots range from 200 to many more . Watch a report on the alleged attacks » . An art gallery director in Urumqi told CNN that thousands of people gathered on the streets on Thursday . `` People are protesting here right now . It 's all Han people , '' he said , declining to give his name because of safety reasons . `` Since August 3 , the Uyghurs have been stabbing the Hans with needles with an unknown virus . People are all very scared . '' A spokeswoman for China 's Foreign Ministry said she did not know about the protests . `` I have not yet received news of this , but the Chinese government is capable of upholding stability and social unity , '' Jiang Yu said . A receptionist at a bank in the area also told CNN about the protests . `` I heard that today , even during the protest , some people got stabbed , too . People are angry that the government is not doing much against the Uyghurs ' needle stabbing , '' said the woman , who also was afraid to give her name .
Report : Stabbings occurred in China 's Xinjiang Uyghur Autonomous Region . Ethnic-fueled violence has plagued the regions 's capital , Urumqi . Riots occurred between predominantly Muslim Uyghurs and ethnic Han Chinese . Witness : Govt . text messages warned syringes contained unknown disease .