Authorities say all schools in Nashua will be closed Monday due to a threat of violence directed toward two schools in the district.
A Nashua Police Department lieutenant says a school administrator received the threat via email on Sunday. That administrator contacted police.
Nashua School District Superintendent Mark Conrad said the district was working with police to determine the credibility of the threat.
"We have received a detailed threat of violence to harm students and staff at both high schools," Conrad said in an announcement on the district website.
"The threat is specific to tomorrow (Monday)," he said. "Because the threat is specific and extends to several schools, we will be cautious and close all of our public schools in Nashua tomorrow, Monday, December 21st. I do expect our schools to reopen on Tuesday. I regret any difficulties this creates for working parents but safety must remain our first priority. Thank you."
The district includes 12 elementary schools, three middle schools and two high schools.
School district Superintendent Mark Conrad said in a statement that students and staff at Nashua High School North and Nashua High School South were threatened with harm.
Lieutenant Kerry Baxter says schools in the district will have extra patrols on Monday.
An investigation is ongoing.
The threat of violence is the third against a school district in the past week.
Los Angeles officials ordered its public schools closed last Tuesday, after officials there said they had received an emailed threat mentioning violence against students, including attacks, assault rifles and an implication of explosive devices, police said.
The LA closures, made by the school district, came as police in New York City said they had received a similar threat for the city's school system, but the NYPD deemed it not credible, and schools remained open.
The FBI eventually determined that the threat against the Los Angeles schools was also not credible, Los Angeles Mayor Eric Garcetti said when he announced that classes would resume Wednesday.