A threatening phone call reported Monday afternoon at Matawan Regional High School prompted a lockdown at schools across the Matawan-Aberdeen Regional School District before authorities determined the threat was not credible, police said.

School administrators reported the call to the main office, and the school’s resource officer and district staff immediately placed the high school on lockdown.

Lockdown procedures were also implemented at all other schools in the district as a precaution.

Officials said that no credible threat was found and that all students and staff are safe. The nature of the threat was not immediately provided.

Police said officers would continue to maintain a presence at school buildings. In a letter to the school community Monday, Superintendent Nelyda Perez said classes will resume as scheduled on Tuesday.