One DeKalb County school was evacuated and four others were placed on lockdown after new threats were made against schools in the Dunwoody High cluster Thursday morning.

About 7:20 a.m., someone called in a bomb threat to Dunwoody Elementary School, Dunwoody police spokesman Officer Anwar Sillah said.

“Out of an abundance of caution, the school was evacuated and cleared by officers,” he said. “We also received threats at Chesnut Elementary, which was briefly placed on lockdown.”

IN-DEPTH: Threats disrupt day, scare parents

Dunwoody High School, Vanderlyn Elementary in Dunwoody and Montgomery Elementary in Brookhaven also received threats, according to school officials.

Authorities in both cities say the threats appear to be a case of swatting, which is intended to elicit police response and create public panic.

“We have found no credible threat to our schools,” Sillah said.

Operations at all five schools were delayed. At Dunwoody Elementary, students were placed in holding areas in the cafeteria and gym. At Chesnut, students were locked in bathrooms. The others remained on lockdown until police concluded a sweep of the schools.

Montgomery Elementary School was on lockdown Thursday morning while Brookhaven police investigated reports of a bomb threat. JOHN SPINK / JSPINK@AJC.COM
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Area elementary schools have been placed on lockdown several times in recent weeks following a series of phone calls and social media posts that police said were “prank threats.”

MORE: Cops: Threat to 'shoot up' DeKalb elementary school came from outside U.S., was not credible

When Dunwoody police were made aware of the first social media threat to “shoot up” a city school in November, they launched a full investigation with the help of DeKalb County school police.

The series of posts came from an IP address outside the United States that was used to send similar messages threatening schools in Canada and elsewhere, police Sgt. Robert Parsons said.

Since then, more social media messages and calls have come in threatening DeKalb County schools, some by name. Silwah said Thursday afternoon the newest threats appear to be related to those in November.

RELATED: Dunwoody elementary schools keep getting 'prank threats,' police say

Katie Frame, whose son is a fifth-grader at Dunwoody Elementary, commended school administrators for their quick response but said she would like the school district to keep parents better informed. Conversations with her son have been tough with little to go on, she said.

“He’s a little nervous,” Frame said. “He wants to know whats going on, and he wants to know why people would do that. He wants to know if he's safe at school, and he should be. We should not have to have these conversations.”

According to Dunwoody police, federal authorities are helping DeKalb school police with the investigation. It is not known why the schools are being targeted.

—Please return to AJC.com for updates.

In other news:

Police said two hikers made the call after they discovered the body near the Main Street Playground. Officers believe the woman was shot on the trail.