A bomb scare at the Dawsonville branch of the U.S. post office Monday afternoon ended when authorities discovered that a smoke detector was the source of a suspicious beeping from a trash can.

The Georgia Bureau of Investigation’s bomb disposal unit had responded to the scene, along with the Gainesville police and fire departments.

Authorities arrived at about 1:30 p.m. after the manager of the post office reported a loud beeping sound coming from a trash can outside the building.

Brenda Mize, the manager, said she heard the beeping after she left the post office to go next door to Regions bank.

"I gave the trash can a cursory look and didn’t see anything," she said.

Mize then reported the noise to Gainesville postmaster Leo Helme.

At the time, three employees and about 15 customers were in the post office.

"The (customers) were lined up to the door," she added.

Linda Orenstein had parked her car in front of the post office.

"I heard the beeping sound as I got out of the car," she said. "I thought somebody’s car alarm was going off."

Soon after she entered the post office, a police officer arrived and told everybody to leave. She walked to the Atlanta Bread Co. at the end of Regions Plaza, which includes the bank, the restaurant, post office and a Verizon Wireless store.

Orenstein bought a sandwich. Moments later, she and other customers were ordered by police to leave the business.

Gainesville police closed a portion of Dawsonville Highway around the post office, as well as neighboring Jackson Electric Membership Corp. offices.

Police also rerouted Dawsonville Highway traffic at McEver Road through the McEver Corners shopping center.

Shortly after 3 p.m., GBI used a robotic device to investigate the cause of the beeping.

Business and traffic returned to normal at about 4:15 p.m.

Lt. Brian P. Kelly, spokesman for Gainesville police, said no threats had been issued to post office employees.

Gainesville police are still investigating the incident "to determine the circumstances around the placement of the item," Kelly said.

The department is asking that anyone with information call 770-534-5254.