Employees are back to work after the Richard B. Russell Federal Building and Courthouse was given the all-clear after a suspicious package was found Monday morning.

The U.S. Marshals Service evacuated after the package, which turned out to be a backpack filled with old clothes, was spotted outside the building at 75 Spring Street, Officer Kim Jones told The Atlanta Journal-Constitution.

Deputy U.S. Marshal Gretchen Fortin told Channel 2 Action News that an employee saw a backpack near a trash can at the entrance of the building.

The backpack and a tote bag were removed from the trash can by a robot and were X-rayed before being opened, according to The Associated Press. Authorities use bomb robots to scan areas for threats.

Streets in the area were blocked for about two hours.