A video of a child being crushed by a minibus and ignored by passers-by has ignited a new bout of soul-searching in China with web users questioning whether ethics are slipping amid rapid change in the country.

The footage, which police told state news agency Xinhua was authentic, shows five-year-old Yan Zhe crossing the street in front of the parked bus, which knocks him over as it pulls away.

A woman, believed to be the boy's mother, is in tears as she rushes to an approaching car for help, only for the vehicle to back away. Several passers-by walk on while others stand around.

It was 10 minutes before another motorist took Yan to hospital, but the boy died on the way, Xinhua reported.