The situation occurred around 8 a.m., while some students were still being dropped off. Approximately 700 students attend the school.
Officials were not able to capture the man. The school was locked down until around 10:20 a.m., when parents were invited back in.
The school will release surveillance tape to try to track down the man, the story said.
Mayor Brian Stack was quoted as saying, "The school security followed all the proper protocol, the teachers did a terrific job today, everyone -- the entire staff -- came together."