Public schools in Nashua, N.H., will be closed Monday in response to what district officials described as "a detailed threat of violence to harm students and staff" at both local high schools.
In a statement posted on the website of the Nashua school district, Superintendent Mark Conrad said he and his staff are working with police to determine whether the threat is credible. The threat made specific reference to Monday, he said.
"Because the threat is specific and extends to several schools," he said, "we will be cautious and close all of our public schools in Nashua tomorrow."
He added that he expects schools to reopen Tuesday. "I regret any difficulties this creates for working parents but safety must remain our first priority," he said.
Nashua police said in a statement that "several state and federal law enforcement agencies" are involved in the investigation.
The public high schools are Nashua High School and Nashua High School South. The closures will affect over 11,400 students in the public school system.
Two area private schools, St. Christopher School and Nashua Catholic Regional Junior High School, said in statements posted on their websites that they would also be closed Monday.
New Hampshire Governor Maggie Hassan issued the following statement via Facebook: "Public safety is any government's most important responsibility — especially at our schools — and we are closely monitoring the situation in Nashua."
Sunday's threat is the latest incident to affect public schools. New York and Los Angeles school systems both received menacing hoax messages last week — leading to closures in L.A.
And in Cambridge this month, a series of anonymous shooting threats to public schools led to heightened security measures.
Reenat Sinay can be reached at reenat.sinay@globe.com.