Fourteen people were injured when an escalator carrying commuters upward went into reverse at a subway station in the South Korean city of Seongnam, south of Seoul.

The incident occurred on Thursday morning when an escalator of about 9 meters in length came to a temporary halt before beginning to move in the opposite direction.

Security camera footage shows escalator riders falling as the conveyance begins to move in a downward direction.

Local media say three people were taken to hospital after sustaining injuries to their backs and legs.

A witness told public broadcaster KBS that he heard what sounded like broken equipment before seeing someone at the top of the escalator fall down.

A man in his 30s said he feels scared as the station is on his commute. He added that there should be an investigation into how inspections of the escalator have been conducted.

Local media say the device, which was installed in 2009, was declared to be in good working order after an overhaul in May. But the mechanism designed to prevent the escalator from going into reverse was reportedly not functioning properly in the lead-up to the incident.

Police on Tuesday plan to conduct an inspection in which experts will offer an assessment. The transport ministry also says it will thoroughly investigate whether inspection and maintenance procedures have been conducted properly.