Maranacook Community Middle School and Maranacook Regional High School will reopen for classes Friday, according to officials. The schools were closed Thursday following the discovery of a threatening message Wednesday in the girls’ bathroom at the middle school. Andy Molloy/Kennebec Journal

READFIELD — Maranacook Regional High School and Maranacook Community Middle School will reopen Friday after being closed Thursday due to a threat that was found in a middle school bathroom, officials said.

A threat was found written in the girls’ bathroom at the middle school Wednesday afternoon, Superintendent Jay Charette said Thursday in an update to the public.

The decision to close the high school Thursday was driven by the school’s close proximity to the middle school. The buildings are next to each other on Millard Harrison Drive.

Charette said school officials do not have a suspect and the investigation is ongoing. The nature of the threat had yet to be disclosed as of Thursday afternoon.

Charette asked families to check if their children know anything about the threat or the incident. Anyone with information is asked to contact Maranacook Community Middle School Principal Rick Sirois at 207-685-3128, ext. 1155, or Deputy Nathan Johnson, the school resource officer, at nathan_johnson@maranacook.com.

When the schools reopen Friday, there will be increased security, including more deputies from the Kennebec County Sheriff’s Office when students arrive, modifications to the daily routines, a revised procedure for leaving classrooms and a constant presence of administrators in hallways.

The initial post from the school district Wednesday night reported that Johnson had recommended the middle school closure, and was investigating the incident with others from the Sheriff’s Office, where he works.

Lt. Chris Read of the Sheriff’s Office said Thursday morning the matter remained under investigation.

Maranacook Regional High School and Maranacook Community Middle School are part of Regional School Unit 38, which enrolls students from Manchester, Mount Vernon, Readfield and Wayne.