MARTINS FERRY — The Martins Ferry City School District’s investigation into who wrote a threatening message inside an elementary school bathroom discovered Monday is underway, said Superintendent Jim Fogle.

Two messages were written on bathroom stalls at Ayers Elementary School. One stated, “I left a bom(b). U have 15 minutes” and the other stated, “I left a bomb.”

Martins Ferry Police Chief John McFarland on Monday said it appeared to have been written by a child.

The school was evacuated and the children were walked over to the neighboring high/middle school building. Parents were alerted of the situation via the district’s Rider Watch emergency call system at about 11:50 a.m.

Parents of elementary students were permitted to pick up their children. Children whose parents could not get to them at that time were sent home at the end of the school day.

“The district takes threats to the safety of its staff and students very seriously and is fully investigating the matter,” Fogle said Wednesday. “Presently, the building principal and the district’s school resource officer are working in coordination to identify the person responsible for the message. Once the investigation is complete, and the responsible party is identified, the district will take appropriate action.”

Fogle did not elaborate on what kind of disciplinary action might be taken against the person, if it is a student.

Because of the threat, Martins Ferry police officers searched the building but found nothing. A bomb-sniffing dog was brought in from Zanesville, Ohio, to also search the building.

The district was set to resume school as usual Tuesday, but a snowstorm that dumped at least 6 inches of snow across the Ohio Valley forced classes to be canceled. Wednesday was the district’s scheduled remote learning day, which is related to the COVID-19 pandemic.