Australian authorities have released security images of a child falling between a train station platform and a train, as a reminder to parents to stay vigilant during the busy school holidays.

A train stops at a Sydney station, and a woman pushes a buggy toward the open doors, in the CCTV pictures.

As she prepares to lift the buggy onto the train, the child walking beside her plunges into the gap between the platform and the train.

The woman then raises her arm to draw the attention of station staff, while passersby pull the apparently unharmed child back onto the platform.

"A simple thing such as holding your child's hand when moving around stations and boarding a train can help prevent them from being seriously injured or worse," Andrew Constance, the transport minister of New South Wales, said in a statement.

The woman's face was blurred in the footage and a government spokesman said she could not immediately be reached for comment.

The clip was widely shared on social media.

In another clip released by the government, a child falls face first after tripping in the gap between train and station while disembarking.

A third shows a young person running down the station stairs, only to trip and fall down several steps before hitting a handrail post.

More than half of train station accidents on the 178-station Sydney Trains network take place at the three busiest stations in the city's central business district, Chief Executive Howard Collins said.

"The most important message I'd like to share with parents is please don't rush around stations or platforms," he added.

In 2010, a 15-month-old boy escaped with only minor cuts and bruises when an approaching train hit his stroller, which had rolled over the edge of the platform.