A security guard in Anhui province has been arrested for molesting and raping more than 10 primary school girls over a three-year period, Xinhua News Agency reported on Monday.

According to officers at the procuratorate of Wuhu's Jinghu district, Ji Songgang, 43, a security guard at a boiler factory in Wuhu, approached the victims, all between the ages of 7 and 10, when they traveled alone on their way to school or home between May 2010 and April.

The man, who served nine years in prison for rape on an earlier conviction, would look for children around primary schools in urban areas, and accost girls traveling alone, offering to escort them or help them with homework.

When the girls responded, Ji would con or coerce them to come to remote residential buildings or makeshift bathrooms, where he would molest and rape them, police said. During the crime, he would also verbally threaten, gag and seize them by throat to make them obedient.

He threatened to kill the girls' families if they reported the crimes, the victims told their parents. Ji's crimes were only alerted to police last month after a young victim’s parents noticed her acting strange.