Four state buildings reopen after evacuation in Atlanta

Updated at 1:18 p.m. ET

ATLANTA Four of the five state buildings evacuated in Atlanta Tuesday morning have reopened, reports CBS Atlanta.

Hundreds of state workers were evacuated while the Georgia State patrol brought in bomb-sniffing dogs to check buildings for explosive devices.

The threat was called into the building that housed state lawmakers' offices.

Just before noon, police said the building was safe and employees returned to work.

Investigators are working to determine where the threat originated from.

There have been a series of evacuations across the United States Tuesday morning. Richmond International Airport has reopened its terminal following a threat that prompted an evacuation earlier.

Concourse D at Hartsfield-Jackson Atlanta International Airport was also evacuated after an explosion Tuesday morning in a maintenance shed near the concourse, but has since reopened.

Meanwhile, Princeton University is currently under evacuation after receiving a phoned in bomb threat against multiple buildings, reports CBS New York.

Dan Day, a school spokesman, says employees were told to leave the central New Jersey campus just before 10:30 a.m. Tuesday.

No classes are in session, though some summer programs are.