Chattanooga police officers are standing down after responding about an hour ago outside the Hamilton County courts building.
A large EMS van and a firetruck pulled up near the building have withdrawn and police are taking down crime scene tape they used to seal the block bounded by Market and Cherry streets and Sixth and Seventh streets.
Earlier, the bomb squad was on the scene and a handler took a dog inside the building briefly.
Police have provided no information about the call-out.
Chattanooga police have blocked Market and Cherry streets because of what is believed to be a bomb threat at the Hamilton County courts building.
Squads of police officers and investigators have cordoned off the block between Sixth and Seventh streets. A large EMS vehicle and a firetruck are on the scene.
Police officials have provided no information, but the bomb squad has been seen at the site.