A teacher who murdered four elementary school students and injured 12 others in central China has been acquitted after she was declared a schizophrenic by experts, the state media reported on Thursday.

Liu Hongwen, a former teacher at Guangyi township central elementary school, on trial for attacking students and teachers in Hunan province on September 30, was identified as a schizophrenic by experts.

Liu, who was declared not guilty by reason of insanity, has been hospitalised for treatment, director of the Linwu county public security bureau, Zhang Jianhua said.

Liu was facing trial for slaying four students, wounding nine others and three teachers and kidnapping 65 students at her school. Police investigation had shown that Liu had a history of mental disease.

Following the incident, the school was completely renovated to help students forget the scenes of assaults and classes were resumed in mid-October.