Students were evacuated from Wilbur Cross High School in New Haven because of a bomb threat.
Police said a bomb threat came through an Internet relay at 11:30 a.m.
The students were moved to East Rock and Hooker because it was too cold to have them outside, but are now returning to school.
State police and the New Haven police bomb dogs went through the building.
Police are investigating the IP address the threat was sent from.