Eighteen elementary schools in Shanghai have started a course on self-protection to keep children from falling victim to sexual assault.

"Recent cases of child molestation were committed by school faculty. Kids usually take no precautions against people they believe are kind, but this may also be a source of danger," said Ding Limin, headmaster of the Primary School Affiliated with the University of Shanghai for Science and Technology and a founder of the course in the schools.

A primary school principal and a government employee in Wanning, Hainan province, were detained on May 14 on suspicion of sexually assaulting six schoolgirls. Yang Shifu, a teacher in Nanyang, Henan province, was detained on May 23 on suspicion of molesting female students since early last year.