NEWAYGO, Mich. (WOOD) — Three students have been charged for making threats against Newaygo County schools.

A 15-year-old has been charged with making a threat of terrorism against Newaygo High School on Dec. 6, the Newaygo County prosecuting attorney said in a release.

A 12-year-old has also been charged with threatening to commit violence at Newaygo Middle School on Dec. 8, the prosecuting attorney said.

Those two charges come after the Oxford High School shooting on Nov. 30. Over 100 districts statewide have had to shut down due to copycat threats.

Although there has been an increase in school threats, the prosecuting attorney says it is not a new problem. Officials say a 14-year-old was charged on Nov. 12 for making a bomb threat against Hesperia High School on Nov. 8.

“Each and every threat made in our community will continue to be fully investigated by local law enforcement and treated as legitimate until proven otherwise,” the prosecuting attorney said in the release. 

All of the threats were found to be not credible, officials say.