Police evacuated workers from City Hall on Wednesday morning after officials received the third threat in three weeks about a supposed bomb there.
Police were notified at 9:42 a.m. that a threat had been received, they said.
Officers began searching the building at 222 W. Hargett St. after all employees and visitors were outside.
The two previous threats were on Mondays — May 14 and 21. No evidence of any explosives was found either time.
There have also been bomb threats phoned to schools in Raleigh in recent weeks, also without any evidence of a bomb being found.
The building, also known as the city's municipal building, is on a parcel on the north side of West Hargett Street between South McDowell and South Dawson streets with the former Raleigh police headquarters and a parking deck.
Workers were let back into the building shortly after 11 a.m., and it was opened to the public a brief time later, police said.