A brave university student climbed onto the Railtrack underneath a train to rescue a four-year-old boy that tumbled off the platform and was trapped in the narrow space between the carriage and the platform.

The incident was filmed in the city of Lanzhou in the northern Chinese province of Gansu on 14th June.

The four-year-old boy fell from the platform and ended up on the track. Commuters immediately notified the train driver not to pull away.

A university student from the Chinese megacity of Chongqing, who preferred to remain anonymous and refused to be photographed by the cameraperson, jumped down into the narrow gap to rescue the child.

According to the news site Baidu, the young man, who travelled to Lanzhou with a group of fellow students, even had to remove his belt as the buckle was catching in the narrow space.

Both the student and the young boy were unharmed in the incident.

In the footage, the boy is seen lying on the ground between the bottom of the train and the platform.

The youngster appears to have his legs trapped under the train and a plastic bag covering his head.

The student lowers himself into the narrow gap and frees the boy before lifting him up to others on the platform.

Onlookers then lift the young man up onto the platform as the video ends.