A station agent reported around 9:35 a.m. that a package brought onto the concourse level by a homeless person was suspicious, and BART and San Francisco Municipal Transportation Agency passengers were evacuated, BART spokesman Linton Johnson said.
Passengers were asked to enter or exit the system at the Embarcadero or Powell Street stations.
BART trains ran through the station without stopping, and the system did not experience delays because of the closure.
Bomb-sniffing dogs responded to the station and found nothing wrong with the package, which appeared to be some kind of battery pack, and the station was reopened, Johnson said.