The package was found at about 1 p.m. and transit police and a bomb squad responded to investigate it.
Trains were being held outside the San Carlos station while police conducted the investigation and SamTrans set up a bus bridge to take passengers between the Belmont and Redwood City stations. The bus bridge has since been canceled.
The investigation took about an hour and, once the package was found to be harmless, it was removed from the station, Dunn said.
As of about 2:30, however, there were still some residual Caltrain delays.