WASECA — Prosecutors said they plan to appeal the dismissal of six charges against a 17-year-old boy accused of plotting to kill his family and attack his southern Minnesota high school.

The teen appeared in a Waseca County courtroom Wednesday for a hearing on whether he should be sent to adult court. The hearing was postponed while prosecutors appeal the dismissal of attempted murder and attempted damage to property charges.

A judge Monday dismissed those charges, but let stand six counts of possessing explosives.

The teen was arrested in April after bomb-making materials were found in a storage locker in Waseca, 70 miles south of Minneapolis.

Police said they also found guns, explosives and a journal that outlined a plan to kill his family and fellow students.