GRAND RAPIDS, Mich. (WOOD) — Grand Rapids Public Schools is telling parents that an apparent threat to two school buildings has not been found to be credible and classes will continue at University Preparatory Academy and Ottawa Hills High School Friday.

The district recognized parents’ concern, saying worry led some 350 University Prep students to either leave early or not attend at all on Thursday. A GRPS spokesman did not immediately have a count on how Ottawa Hills attendance was affected.

In a call sent out to parents, GRPS said that the threatening comments came Thursday morning from a social media post that uses a fake name. GRPS said it called police and upped security.

“These threats have not been found to be credible at this time. We are continuing with class as usual. Our buildings and our students are safe,” a spokesman stated. “We are grateful that our scholars reported these postings immediately.”

Grand Rapids police are investigating the social media post to learn who is behind it.