The Calhoun Police Department responded quickly, and students were moved to the school's gymnasium at around 2 p.m.
Police Chief Garry Moss said the police brought in the department's K9 unit.
"We have done a sweep of the school, and teachers have gone through their classrooms looking for anything suspicious," Moss said on Friday.
Moss praised the school's swift evacuation plan saying the faculty and staff acted quickly.
Moss said he didn't want to speculate on whether or not the threat was a prank.
"We always take them seriously," he said.
Det. Lt. Tony Pyle of the Calhoun PD, said several students reported that the note on the wall had been there for several hours.
“It was reported by more than one student,” Pyle said.
The police department has no leads at this time, Pyle said.
“The investigation it as a standstill, but we are still working on it,” he said.
Students were released on schedule Friday afternoon after the school was cleared.
"We appreciate the support of our local law enforcement. They provide a great service to our schools and help ensure that our schools are safe," said Calhoun City Schools Superintendent Michele Taylor.
Friday’s bomb threat comes on the heels of a string of bomb threats that occurred in the county before students were released for Christmas Break.