Police are hunting a man, believed to be suffering from a psychological illness, after he stabbed three holiday-making youngsters with a knife in Tin Shui Wai on Sunday night. The man is described as being between 40 and 50 years old, 1.6 metres tall, with short hair and of medium build. At the time of the attacks he was wearing a T-shirt and a pair of dark-coloured shorts and carrying a black backpack. There were separate attacks carried out at three different spots along a cycling track near Tin Ying Road in Tin Shui Wai. Police said that the victims did not know each other or their attacker. Officers searching for clues found a 25cm fruit knife in the nearby brushwood. Two of the injured - a 16-year-old girl and an 18-year-old man - were in stable condition in Tuen Mun Hospital yesterday. The youngest victim, an 11-year-old boy who suffered cuts to his forehead and stomach, was discharged after treatment. The 18-year-old man, who was cut on his neck, recalled his ordeal in the hospital. He said he was celebrating the Mid-Autumn Festival with his friends when the man suddenly came up behind him and put some glow sticks around his body, saying: "What's up?" He thought somebody was playing a joke, but the attacker then pulled out a knife. The victim struggled to duck away, but was injured in the tussle. He said the man, still holding the knife, then turned towards his friends, who ran away in terror. After this the man left. Police officers returned to the scene yesterday to continue their investigation. The case is being handled by Yuen Long district crime squad. In August, a drug addict who attacked four strangers in a two-day chopping spree in Tseung Kwan O last year was jailed for five years.