An Anchorage high school student was arrested after posting a photograph of guns on social media and warning others to stay away from school Thursday, authorities said.
The posting prompted multiple calls to police from worried students Wednesday evening.
"They were afraid for their safety. They were afraid for their friends. And they called us," police spokesman MJ Thim said. "They did the right thing."
The message was posted on Snapchat and included a photo of several guns inside a case, Thim said.
The student was arrested Wednesday evening and taken into custody at McLaughlin Youth Center in Anchorage, Thim said.
Charges have been forwarded to the state's juvenile justice system.
Police said the posted threat warranted charges even though officers determined no schools were imminently threatened.
"A natural conclusion is that this is a threat that somebody will come and shoot up the school," Thim said.
Anchorage police have not identified the student, his school or charges because he is a minor. Anchorage School District officials also are not naming the student or school.
District Superintendent Deena Bishop sent an email message about the arrest to families, staff and others in the city.
"We appreciate the students, families and staff who came forward to share the information," Bishop wrote. "It allowed us to deal with this situation swiftly to ensure the safety of our schools."