More than 50 police officers swept the hills from Western to the Peak yesterday in an eight-hour operation against illegal immigrants - but returned empty-handed.
Police Tactical Unit and local officers began operations at 7am and identified 13 new suspected black spots in addition to 18 hiding spots known to be used by illegal immigrants.
They include a guard house in a garden in Magazine Gap Road, where abandoned clothing and bottles were found.
The search came after a robber broke into the home of Hongkong Bank chairman John Strickland on Wednesday and tied up his wife, Anthea, 57, before escaping with $100,000 in cash and jewellery.
Police denied crimes were on the increase on the Peak.
'Before, IIs would stay over before targeting rich households. Now they appear to arrive by transport to commit crimes,' Central divisional commander Ng Sai-kuen said.