Eric Sanville, 39, was arrested Thursday at his home in Norwood, Delaware County.
Authorities said the alleged activity occurred over the last year and involved victims, including one in Sweden.
According to his Facebook profile, Sanville has worked for the North Penn School District for nearly nine years. He most recently served as a special education teacher at Gwynedd Square Elementary School but will not be in the classroom when a new school year begins Monday.
Meghan Eveland is a district parent, though her child does not attend Gwynedd Square Elementary.
"I think it's concerning to every parent in this school district," Eveland said.
"My daughter has autism; she's on the spectrum. I just want to make sure everyone is safe and parents have peace of mind," she added.
Federal investigators allege Sanville communicated with approximately 25 girls between the ages of 9 and 13 on Snapchat, sending and receiving pornographic pictures and videos. He is charged with manufacturing and attempting to manufacture child pornography, a charge that carries a potential prison sentence of 15 to 30 years.
The North Penn School District notified families by email Thursday, stating that Sanville has been placed on leave and is prohibited from district property and from contacting students.
The criminal complaint details a number of disturbing allegations. Among them, Sanville used two Snapchat accounts while pretending to be a minor, telling young girls he wanted to start a group chat to share "spicy" pictures. Prosecutors allege he would ask the girls to show him nude pictures of themselves before he would let them into the group chat.
"People are like this everywhere, but having it in our school district is very concerning," Eveland said.
Leslie Slingsby, CEO of Mission Kids, Montgomery County's child advocacy center, said the case highlights the importance of discussing online safety with children.
"I think this is a clear situation where we realize that it really can be anybody who is offending or interested in offending against our children," Slingsby said.
She encouraged parents to have regular conversations with children about online interactions and to reassure them they are not at fault if they believe they have been victimized.
"We want to avoid blame. We want to avoid judgement. We don't want to interrogate them, but we do want to preserve messages, usernames, account info, and we want to contact law enforcement," Slingsby said.
According to authorities, one case came to light after a victim came forward, while another was flagged by Snapchat.
Parents are calling for continued communication from district leaders as the case moves forward.
"As long as the school district is transparent with us, we will be willing to listen," Eveland said.
Authorities say Sanville admitted to creating the Snapchat accounts. The North Penn School District said it does not appear that any students at Gwynedd Square Elementary or in the local area were involved.