HAVERHILL — Officials at Nettle School said they called in a police Thursday afternoon after a troubling message was discovered written on a bathroom wall in the building.

An email sent to parents by school officials said police were called in after "a single word'' that concerned officials was discovered.

The email said police did a sweep of the building and determined there was no risk to students. 

"They (police) responded immediately and cleared building,'' the email said. "We did not evacuate the building.''

School officials did not say what word was discovered written on the wall, or whether the student who wrote it has been identified or disciplined. Police would release no other information.

Here is the entire email, written by Nettle Principal Tim Corkery and released by the School Department:

"Parents,

Today we had a student write a single word on a bathroom wall that required us to call the police. These behaviors are disruptive to the learning environment and force school and police to use resources that could be better utilized elsewhere. We continue to remain vigilant on these types of incidents and take all steps to determine who is responsible. We did ask the police to do an additional sweep of building. They responded immediately and cleared building. We did not evacuate the building.''