Branford High School was evacuated after a bomb threat was left on a voicemail and the school closed early on Thursday.
The superintendent's office reached out to police just before 9 a.m. about a message on an office phone at the high school that said an explosive device might be placed within the school facility.
Police said the students and staff were taken to Walsh Intermediate School and students were picked up from the Walsh school.
As a precaution, Branford High School closed early.
Police investigated and determined the school is safe. They are investigating to find out who made the call.
East Haven High School was also evacuated after a bomb threat was made through a voicemail, but classes have resumed.
Police said they do not know if the two incidents are connected, but Branford police said they will be in contact with East Haven police.
