Columbia High School was temporarily on lockdown Monday after a school resource officer confronted a man with a gun, the DeKalb County school system said.

The gunman was not a student at Columbia, and the school was put on lockdown while the officer attempted to apprehend the suspect, according to Quinn Hudson, spokesman for DeKalb schools.

Students were allowed to leave around 3:50 p.m., about five minutes later than normal dismissal time, Hudson said. No injuries were reported.

DeKalb police officers were assisting with the search for the gunman. A description of the suspect was not released.

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