The investigation involves four girls and one boy, ranging in age from 15 to 16.
Reports were made to Etiwanda and Rancho Cucamonga high schools Wednesday after photos of nude girls were posted Monday evening on a social networking site. An investigation by a San Bernardino County Sheriff's detective revealed the account belongs to a 16-year-old male student at Etiwanda High School.
The sheriff's department says of the four images, two have been identified as female students at Rancho Cucamonga High School. The other two girls have not been identified.
Interviews with authorities confirmed at least two female students from Rancho Cucamonga High School sent the images to the male student in the past.
Investigators are trying to figure out if the boy's account was hacked, or if he posted the photos. They are also determining if the four girls who sent out the nude pictures of themselves will face charges.
According to sheriff's department, anyone sending a nude or partially nude photo of people under 18, whether of themselves or other people, violates child pornography laws.
No arrests have been made. Anyone with information is asked to call the Rancho Cucamonga station at (909) 477-2800.