The lockdown took place around 11:30 a.m. Friday at the school at 1 Lincoln Blvd.
"There is no active shooter threat at Central High School," said Av Harris, director of Legislative Affairs/Public Policy City of Bridgeport.
Harris said students were circulating a “Snapchat” photo around the school and a student, who was possibly the suspect was immediately located and detained.
"As a precaution, a perimeter of the campus was set up with the help of patrol," he added.
School Security, school resource officers, and school officials swept the building as a precaution.
To help give students a sense of calm, additional school resource officers will be stationed at the school for the day.
Click here to follow Daily Voice Greenwich and receive free news updates.