The Berlin fire brigade and other emergency services moved out to a larger operation at the Friedrichstrasse station on Monday.
According to a railway spokeswoman, an S-Bahn train had to be evacuated there, which had broken down shortly before the station due to a technical fault.
The fire brigade spoke of a "mass casualty incident", several people had circulatory problems.
At the time of the incident, it was very hot in Berlin.
It was initially unclear how many people were actually injured.
Because of the problem, train traffic on the route in central Berlin had to be stopped first.
This affected not only the S-Bahn, but also long-distance traffic.
According to information from the railway and the federal police, some passengers managed to get out of the defective S-Bahn on the open route and walk on the tracks towards the station before the evacuation operation.
That is illegal and dangerous.