WHITMORE LAKE, Mich. — Police say four teens have been arrested in connection with a threatened school shooting in southeastern Michigan.

Whitmore Lake Public Schools Superintendent Tom DeKeyser received a threat about “shooting up” a school building shortly after classes let out Tuesday, and Northfield Township police officers deemed the threat to be credible. They arrested four suspects, ages 16-18, who were being held Thursday in jail or a juvenile detention center.

Police say they also recovered a weapon.

All four suspects are current or past students in the school district about 30 miles west of Detroit.

The Livingston Daily Press & Argus reports all schools in the district were closed Wednesday.