HONG KONG - The police in Hong Kong have arrested two workers from an escalator company following an incident at a Kowloon mall that left shoppers injured.

The men, aged 22 and 52, from Otis Elevator Co, were arrested for attempting to pervert the course of justice, by allegedly tampering with one of its key braking systems during an official inspection into what happened at the Langham Place mall, the South China Morning Post reported. The duo are out on bail and are required to report to the police next month.

Shoppers at the mall lost their balance and fell as the 45m escalator reversed direction last Saturday. Eighteen people were hurt.

A woman who injured her leg in the incident said the escalator was moving twice as fast as usual. More than 10 people piled up near the base of the escalator, a witness said.

The Electrical and Mechanical Services Department said a damaged driving chain may have been the cause of the incident. A braking device may also have failed.

An Otis spokesman said the arrest of the technicians came as "a surprise" and the company would defend them, the Post reported. The spokesman added that the firm's legal team is working with the police "to clarify the situation".

A spokesman for Langham Place said it would not comment on the arrest, according to the Post. The mall had said last Saturday that the escalator had just passed a biannual safety inspection last Thursday.

The escalator links the fourth and eighth floors of the Mong Kok mall in Argyle Street, and is one of the longest indoor escalators in Hong Kong.