A person is in custody after threats of violence were made on social media against Argo Community High School in southwest suburban Summit.
Officers arrested someone in connection with the threats around 5 a.m. Monday, Summit police said.
The post shared on social media Sunday afternoon threatened violence against “every class” at the school.
Though the threat didn’t mention a specific day, security was increased Monday morning “at all entrances and in the building,” a statement on the school’s website said.
The police presence will remain in place throughout the day as a precaution, the school said.