Anonymous bomb threats were made to dozens of northern Indiana schools on Thursday night.
The FBI and Indiana State Police have been investigating.
About three dozen schools were sent threat messages by email.
In a news release, the Indiana State Police says they have utilized intelligence resources to look into the threats and have found no suspicious explosive devices in any of the schools.
They continue to try to find out where the threat came from.
Some of the affected schools closed or conducted e-learning days on Friday out of precaution.
