CANTON — The Cherokee County Justice Center, the Historic White Courthouse and much of downtown were quickly evacuated Tuesday morning in response to a bomb threat.

After a second bomb threat later that afternoon and following hours of searching the county’s courthouse using bomb-sniffing dogs, no device was found and businesses and city streets were reopened.

But the county justice system remained shut down until at least this morning and all county workers were sent home early, Cherokee County Sheriff Roger Garrison said.

“Based on receiving a second call from the individual, and based on the specifics of the threat, we are keeping the courthouse closed overnight and will continue to follow leads in the investigation,” Garrison said.

The first threat was called into Atlanta 911 around 11 a.m. from a pay phone in the metro area and a male voice made the threat, leading to the evacuations, said Sheriff’s Office spokesperson Lt. Jay Baker.

A perimeter was established around both county buildings in downtown, Baker said. Bomb dogs from the Cherokee Sheriff’s Office and surrounding agencies arrived on the scene.

The perimeters and interiors of both buildings were searched and no devices were located, Baker said.

“While searches were being conducted, a second bomb threat to the Cherokee courthouse was received by Cobb County 911,” Baker said. “The courthouse will remain secure for the rest of the evening and will resume normal operations (today).”

Garrison said this is only the second time in three years that a threat serious enough to shut down operations at the court facility was received.

“The caller gave the specific type of explosive he planned to use, and it was the type that is extremely volatile,” Garrison said of the decision to close off the downtown area to traffic for much of the day Tuesday. “We wanted to err on the side of caution.”

Garrison said it was a light court day, making it easier to shut down the facility.

About 250 people were evacuated from the court facilities.

Fulton, Cobb and Hall county K-9 units helped in the search for a possible bomb.

Detectives with the Cherokee Sheriff’s Office were investigating the incident.