An Oakland fire official said Amtrak told him one of the trains ignored a red signal as it entered the station. An Amtrak spokesman would not comment on that report.
It appears the Coast Starlight, which operates between Los Angeles and Seattle, hit another train that was loading and unloading passengers. The train already in the station travels between Bakersfield and Oakland.
The moving train was traveling an estimated 15 to 20 mph, officials said. Most of the injuries were minor, but some people had to be taken to the hospital.
The crash is the second significant incident in two weeks in the San Francisco East Bay area where there were injuries to Amtrak passengers.
On Sept. 30, 37 passengers and two crew members suffered minor to moderate injuries when an Amtrak passenger train collided with a truck at a crossing near Brentwood where there were no lights or gates.
The Associated Press contributed to this report.