RUMFORD – Police have suspects regarding Tuesday morning’s discovery of a written bomb threat in a boys’ restroom at SAD 43’s Mountain Valley High School.

However, as of late Tuesday afternoon, arrests had yet to be made in the incident. The threat prompted a nearly two-hour lockdown of 580 students and about 40 teachers and staff while the building was searched for anything suspicious. No bomb was found.

“It’s still an open investigation,” police Detective Lt. Mark Cayer said Wednesday afternoon. “There are suspects. We have conducted several interviews with high school students and staff, and will conduct several more tomorrow. Everybody’s been very cooperative.”

Among students interviewed on Tuesday were a few seen walking in a hallway in the vicinity of the restroom where the threat was found.

“We felt that it was important to talk to them, but the ones we talked to are not considered primary suspects,” Cayer said.

Shortly before 8:40 a.m., the threat was found written on school property inside a boys’ restroom. Refusing to divulge the exact wording of the threat, Cayer said the writer stated that a bomb was in a specific area.

“We made a copy of the written information and provided it to all of the faculty hoping that someone would recognize the handwriting. Now, we’re just waiting for that process to conclude,” Cayer said.

After assessing the situation with police, the school entered lock-down mode at 8:40 a.m.

“It’s standard procedure after assessing the threat,” Superintendent James Hodgkin said in his office in Mexico. “I always feel bad when the school system inconveniences all students because of the actions of a small group of students or one student, but we have to ensure the safety of all.”

With students secured, the school was searched by Rumford police, dozens of district custodial staff and teachers, and state police troopers.

Cayer said Rumford police asked the Maine State Police to bring a dog trained to detect explosives, but the dog wasn’t used, because the building wasn’t evacuated. A state bomb-sniffing dog can only search a building if there is no one in it.

At the school during the lockdown, some students could be seen laughing, waving and smiling from behind classroom windows. Others on the second floor opened windows and joked with passers-by, then said they were holed up due to a bomb threat.

Attempts to enter the front doors were denied by a man who told anyone approaching that the school was locked down.

After the lockdown ended at 11:30 a.m., Principal Matt Gilbert conducted an impromptu school-wide assembly for students and staff.

“Matt will tell them what happened and ask for their assistance in making this not happen again. … Some kids will think of this as a joke and others will get angry at their peers. Then, one of two things will happen: They’ll either deal with it themselves or they will let us know who did it. Our kids are pretty good, so I hope we’ll find out who is responsible and they will be dealt with,” Hodgkin said.