A Chinese man who stabbed 29 school children and three teachers has been sentenced to death after a half-day trial. <br/><br/>The 47-year old unemployed local man, Xu Yuyuan was found guilty of attacking a kindergarten in Taixing city in eastern Jiangsu province last month. <br/><br/>According to the official Xinhua news agency, Xu told the court that his motive was to vent his rage against society. <br/><br/>Prime Minister Wen Jiabao said the outburst of violence had deep-seated roots in the country's social tensions that need addressing. A string of attacks at Chinese schools has killed a total of 27 people and injured more than 80 since March.