Two left-behind children in Southwest China's Guizhou province, May 3, 2014. [Photo/IC]

Legal experts said a lack of awareness among minors, parental negligence and flawed safety systems are often to blame for the sexual abuse of minors.

In China, few parents are aware of the importance of sex education, and often wait until their children are 14 or 15 years old, said Hong Daode, a law professor at China University of Political Science and Law.

Schools only offer physical health classes rather than opening sex education courses, and most minor victims lack awareness of how to protect themselves, he said.

"Because of the lack of sex education, some juveniles may not even realize they have been sexually abused, and don't report to local police," he said.

Between 2010 and 2013, national prosecutors accused 8,069 suspects of obscene behavior involving minors in 7,963 cases, and have charged 255 people with sexually abusing young girls in 150 cases.

Meanwhile, 121 suspects have been prosecuted for luring young girls to participate in prostitution, according to numbers released by the Supreme People's Procuratorate.

Shi Weizhong, deputy director of the top prosecuting department, said 70 percent of the victims were under 14, most of them from the families of migrant workers or a single-parent family.

"Some parents, particularly migrant workers, are too busy to supervise and properly protect their children," he said.

Shi said rapists are usually acquainted with the victims - a neighbor, family friend or stepfather, for instance - and many cases involve repeated abuse over a long period of time.

He criticized loopholes in school safety, saying that schools failed to conduct regular patrols and didn't equip dormito ries with protective measures, thereby presenting criminals with opportunities to enter.

"Many sexual assaults occurred in classrooms and dormitories," he said. "Some even happened at a teacher's podium."

One typical case happened in last May, when a male teacher, surnamed Sun, sexually assaulted a 9-year-old girl multiple times in a classroom of a Beijing primary school. The girl didn't dare to speak out about it, according to Chaoyang district court in Beijing.

Sun sexually abused the girl many times after school, it said.

It was not until the girl's mother found an injury on her body during a bath that the matter was reported to the local police, according to the court.

In September, Sun was convicted of sexually abusing the girl and sentenced to three years in prison by the Chaoyang district court.

Xiao Wei, a spokeswoman for the top prosecuting office, said that the SPP, the Supreme People's Court, the Mini stry of Public Security and the Ministry of Justice jointly issued a notice in October specifying severe punishments for sexual crimes against minors.

Shi said local prosecuting departments will set up agencies and special minor tribunals to handle such crimes.

Prosecutors will also cooperate with public security organs, justice departments and civil affairs departments to improve legal assistance and social aid for juvenile victims, he said.

"Minors, who are physically and mentally immature and lack the ability to distinguish right from wrong, are vulnerable and easily become targets," said Wu Zongxian, a criminal law professor at Beijing Normal University. "Education is the key to preventing sexual assaults."

"After learning relevant knowledge and skills, children will have the ability to identify potential threats, and then protect themselves from being sexually harmed," he said.

In addition, schools and communities should offer more guidance to parents, he added.