
According to Apple Daily, 14 women and four men were injured, some with head injuries.
The 45m-long escalator links the fourth and eighth floors of Langham Place. It is one of the longest in Hong Kong.
Video footage showed it moving upwards, before suddenly going backwards, throwing shoppers off balance about 4pm. Some hung on to the handrail.
The escalator was last inspected on Jan 27. The last routine inspection was on Thursday.
Langham Place, completed in 2004, gets more than 200,000 visitors each day.
One of those injured, a woman, told reporters the escalator was going at twice its normal speed when the incident happened. It lasted less than a minute.