OVER the past two years police have found some 120 hideouts used by illegal immigrants or criminals on Hong Kong Island. Senior Assistant Commissioner (Operations) Benny Ng Ching-kwok announced the figures yesterday at one such hideout, discovered about two months ago, near St Joan of Arc Secondary School in Braemar Hill. Following last week's fatal stabbing of an elderly walker on the Peak, he repeated that the police have a comprehensive plan to protect the public from random violence and assault. Mr Ng said hideouts ranged from abandoned buildings to natural geographical formations providing cover. A discovered hideout might be demolished, or police might decide to wait in ambush. 'This is not a one-off operation. Our intention is to identify all the locations, which gives us a very good idea where illegal immigrants or criminals might hide out, to prevent and detect crimes,' said Mr Ng. Local police were in regular contact with their mainland counterparts, especially those in border areas, with regular exchange of information and intelligence, he said. Secretary for Security Peter Lai Hing-ling said police would be increasing patrols in mountain parks and said the Government was concerned about the recent spate of crimes in the Peak area. But he denied security in the area had worsened; in the first six months of this year there were five robberies and 16 burglaries, compared with four robberies and 17 burglaries in the same period last year. In the first seven months of 1996 there were some 47,000 crime cases, a 10 per cent drop on the same period last year. There was a drop in violent crime cases, but there were 40 more rape and sexual assault cases.