Police responded to Bulkeley High School in Hartford on Monday afternoon due to a bomb threat at the school was placed on lock-in, until police determined the scene was clear.
Police searched the building and did not find any devices, according to police.
Students were told to stay in the classrooms and the doors were shut, according to David Medina, spokesman for Hartford schools.
The bomb squad was not been called in, nothing was evacuated and no one was sent home.
How the threat came into the school is not known.
