Video footage by witnesses showed the packed escalator suddenly reverse direction and pick up speed going down, throwing dozens of people onto the floor.
The cause of the malfunction is still unknown.
Local media reports that two technicians, who work for Otis Elevator Company, have been arrested for what the authorities called “perverting the course of justice."
The pair, who were called to investigate the accident, are suspected of tampering with the escalator after the incident.
Otis has expressed surprise at the arrests and said it would seek clarification from authorities.
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