Six men have been arrested on suspicion of molestation and taking and sharing pornographic images of young boys, the Kanagawa Prefectural Police said Thursday, adding that the suspects are members of pedophile groups and victim tally may top 160.

The suspects, who range in age from 20 to 66, were arrested by police from seven prefectures and allegedly belonged to two separate groups that shared pedophilic information and pornographic images of boys via social networking services.

Four suspects in one of the groups had experience working as escorts and volunteer caretakers for children's camping tours with an aim of taking such photos, the police said. The images included photos actually taken by the men themselves during such tours, they said.

The seven prefectural police agencies involved have been able to build 21 cases so far but believe up to 168 kindergarten, elementary and junior high school students in nine prefectures were victimized by the men.

More than 100,000 still images and videos of child pornography have reportedly been found at homes and locations related to the six men.

One of them, 35-year-old Tetsuya Kaihotsu from Higashiosaka, Osaka Prefecture, allegedly molested seven students of elementary school age at camp sites and other locations between 2014 and 2016, the police said.

He was a member of the nursing staff at a travel agency that specializes in camping tours for students and called on other men to come to the camps as volunteer staffers, they added.

Akira Hashimoto, a 45-year-old elementary school teacher in Tokyo, allegedly molested a boy and took indecent images of him in Tokyo in March last year, the police said.

Kaihotsu admitted to the allegations but Hashimoto denies some of them, they said. The two became acquainted through a social networking service for pedophiles and eventually met other members, the police said.