Fourteen commuters were crushed when an escalator suddenly started reversing inside a subway station in South Korea on Thursday.

Shocking CCTV footage shows the escalator going haywire - causing the travelers to fall backward and pile up at the bottom of the platform at the Sunae Station in Bundang, Gyeonggi on June 8.

Some of the commuters were seen falling over the escalator railings, while others were crushed under the avalanche of people.

Fourteen people were injured. Eleven suffered minor wounds and were sent home after receiving first aid. Three others were taken to a hospital for back and leg injuries.

None of the injuries were life-threatening, local media reported.

Authorities immediately cordoned off the escalator leading to exit 2 of the station following the incident.

Police were investigating the cause of the accident, and ruled out foul play. They said it was unlikely the escalator was 'manually reversed' and suggested it had malfunctioned.