Police and school officials are investigating a bomb threat written on a bathroom wall at a Bismarck middle school.

Students were evacuated from Wachter Middle School, 1107 S. Seventh St., from 2 p.m. to 3 p.m. Thursday at the recommendation of the Bismarck Police Department, according to a release from the school district. School dismissal was delayed by 10 to 15 minutes.

The incident is under investigation.

- Jenny Michael