The school said the students are safe. It issued a statement saying: "Please do not come to campus...During a code yellow lockdown, all students return to and remain inside the building. Activities inside the school continue as normal."
Cary Police Department said the school received an online threat. Specifics about the threat were not released, but investigators have since determined that the threat was not credible.
This was not the only school in North Carolina threatened with violence Tuesday.
The North Carolina Information Sharing and Analysis Center said that 40 North Carolina schools in multiple districts across the state were listed in the threat. The threat also reportedly had dates listed next to some of the schools.
"Law enforcement has determined there is no credible threat. The source has been identified and intervention has been conducted," the agency said in a statement.