Greensburg police said the three female Greensburg-Salem High School students, ages 14 and 15, have been charged in Westmoreland County with manufacturing, disseminating or possessing child pornography after they allegedly took pictures of themselves -- two of the girls nude, the other semi-nude -- with their cell phones and sent them to other students, the Pittsburgh Tribune-Review reported Tuesday.

Three male Greensburg-Salem students, described as 16 and 17 years old, were charged with possession of child pornography after the pictures were found on their cell phones.

Lisa Rullo, former principal of the high school and current district director of student services, said students are made aware of laws and district rules regarding pictures on cell phones.

"We inform the students that it still is child pornography (if they give or possess it) and ... this is something they don't want to have at all," she said.