Students were briefly evacuated at two area high schools Tuesday after separate bomb threats drew police responses, but no evidence of any bombs.

The bomb threats were reported at Oak Hill High School in Wales and Richmond Middle/High School.

The Androscoggin County Sheriff’s Department received a call at 9:01 a.m. from Oak Hill High School reporting that a teacher had found writing on a wall in the school that was interpreted as a bomb threat.

Deputies found nothing when they searched the building with the help of a bomb-sniffing dog from the Maine State Police. Wales Fire Department and Sabattus Fire Department also responded.

The school was cleared at 10:15 a.m., and students and staff were allowed back in the school.

Some students had seen the writing on Monday but ignored it, according to a release from the sheriff’s office.

Police said they are still investigating. They asked that anyone with information about the incident call sheriff’s Sgt. James Jacques or Lt. Glenn Holt at 753-2599.

In Richmond, state police bomb-sniffing dogs searched the school after a student discovered the words “bomb threat” written in pen on the wall of the girls’ bathroom near the gym and cafeteria, which is accessible to both middle and high school students.

The high school gym was also the location of the annual Town Meeting on Tuesday night, and Police Chief Scott MacMaster said the meeting would go on as planned.

The writing was discovered around 11:30 a.m. after which school administrators called police. The school was locked down and Richmond police responded, assessed the situation and met with school officials, evacuating the school around 11:45 a.m. and calling for assistance from Maine State Police dog handlers.

MacMaster said the dogs thoroughly searched the school and found no explosives or other threats.

Students were allowed back into school around 1 p.m., where they attended a brief assembly before returning to classes.

MacMaster said police would work with the school and review video footage to put together a list of potential witnesses. Anyone who saw something amiss may contact school officials or call Richmond police at 737-8518.