A recent high-profile case involving three students who — according to police — attacked and killed a teacher in Hunan province, has raised concerns about left-behind and Internet-addicted children.

Three students aged 11 to 13 mugged and killed a teacher on Oct 18 in a primary school in Shaodong county, according to a police statement that said the youths confessed to the crime.

On Monday evening, Li Qiubing, head of the county's bureau of press, publication, radio, film and television, and Li Zhengrui, head of the county's cultural market administrative enforcement force, were investigated and the latter was removed from his post for poor management. Three Internet bars were shut down for receiving under-aged clients.

Juvenile Protection Law bans youth under 18 to enter Internet bars.

Police said the students went to an Internet cafe on the morning of the killing, then later two of them suggested they go play in a nearby primary school. After they stole food from the school's snack bar, teacher Li Guiyun spotted them and asked them to leave, police said.

To prevent the teacher from reporting their petty theft, the students struck the teacher on her head, chased her into a bathroom and choked her to death with a piece of cloth, police said.

After the teacher died, the trio stole her mobile phone and about 2,000 yuan ($330) in cash, police said.

The students were found the next day in an Internet cafe, arrested and sent to a local juvenile correctional school, where they remain awaiting their appearance before a judge. The case has received wide attention in national media, including from Xinhua News.

The students spent a fair amount of time at Internet cafes, but there is no real evidence these particular youths were addicted to the Internet or violent video games. Questions have been raised as to whether the students' behavior is directly related to any addiction to video online video games, but experts have concluded that a generation raised on the Internet, including violent Internet-based video games can desensitize youths to violence.

"It is commonly known that many children play violent video games online. When children have a lot of access to violent games, they develop less fear, which makes it easier for them to commit crimes," said Tong Lihua, head of Beijing Children's Legal Aid and Research Center.

"People live in a real world, not a virtual world," he said. "It is essential that parents create a real world full of love and fun for children," he said.

Tong also said when children are left at home by parents who work in the cities, it is important to have trained professional social service organizations and personnel to help those children.

Two of the suspects were left-behind children whose parents were migrant workers, authorities said. However, it is not known what sort of home supervision they had in the absence of their parents.

According to the 2010 national census, 35.8 million children under the age of 18 travel with their migrant worker parents, and another 61 million children are left in rural areas when their parents head off to work in cities.

An education report released in April and conducted by Zhang Liangxu, vice-director of the China Youth and Children Research Center, said the structure of migrant families is likely to lead to juvenile crimes.

"There were important links between family factors and juvenile crime. Bad family structure, an improper method of family education, and a poor family economic and cultural environment were the key factors causing delinquent minors," the report said.

Zhang and his colleague Zhao Huijie also conducted a survey in a juvenile detention center. They found that 9.1 percent of juvenile criminals are children from migrant families who are left at home while parents work in the cities, and 9 percent are children from migrant families who move to cities with parents.

"Children from migrant families were not able to adapt to the new environment smoothly. When children move to cities with their migrant worker parents, they need to blend into urban living quickly," Zhang wrote in the report. "However, some children move to the city at a young age, and their parents, busy with work, do not provide enough care and attention. Youths may adapt to city life blindly and in the wrong way. On the other hand, the city is not tolerant enough to cuddle these new residents, providing appropriate assistance and support."

luowangshu@chinadaily.com.cn