Plattsmouth Community Schools posted a statement on its Facebook page Tuesday night saying it has canceled Wednesday classes because of a second threat.
The district says it wants to allow law enforcement adequate time to investigate.
A statement regarding the initial threat states that administrators at Plattsmouth High School received information that two male students ages 15 and 16 were planning an attack on the school.
Cass County Sheriff's Office investigators have interviewed the students and their parents. According to the statement, "investigators determined a terroristic plan was being developed, however, had not been acted on. Personal property was searched with no additional evidence obtained. The weapon that they had intended to use has been accounted for and has been secured."
The two students are in the custody of their parents.
Authorities say there is no threat to students, staff or facilities at this time.
They continue to interview students with knowledge of these allegations. If you or your child has firsthand information that could help with the investigation, you're asked to call the Cass County Sheriff's Office at 402-296-9370.
Plattsmouth Community Schools, the Cass County Sheriff's Office and the Cass County Attorney's Office are working together on this case.
Wednesday will mark one week since police say a 19-year-old gunman killed 17 students and staff at Stoneman Douglas High School in South Florida.