The incident happened in the city of Xining, the capital of China's Qinghai province. A video shows the train arriving at one of the platforms.
A little girl walks by with a woman accompanying her. Seconds later the three-year-old rushes to the train while the woman is distracted by scenes in the train carriage, falling into the gap between the train and the platform.
The woman hurried to save the girl but was unable to do it on her own.
About a dozen people soon came to help and two young men jumped into the gap and pulled the girl to safety.
The incident came only just a minute before the train was scheduled to leave the station, however, after the staff heard the commotion it was quickly ordered not to move off.
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