A 10-year-old girl was raped in her Aberdeen home yesterday after letting in a stranger who knocked on the door of her family's apartment asking to use the bathroom. Detectives were questioning a suspect last night and investigating whether the attack is linked to five unsolved sex attacks on girls aged 10 to 14 in Western in 1999. The Primary Four student was attacked after she returned to her home in Wah Ming House, Wah Fu Estate, at 1pm. She rang her father, a taxi driver, to tell him she was home. Assistant Western District commander (crime) Superintendent Sheung Chi-keung said: 'Minutes later, a man banged on the door and asked her whether he could use her toilet. The girl, who is kind-hearted, let him in. 'The man came out of the toilet and went to her bedroom where she was raped. The sex attacker fled out of the unit and no property was stolen.' Initial investigations showed the rapist stayed in the apartment for less than 10 minutes and no weapon was produced or used. Officers said the girl was alone inside the flat at the time of the attack. Her parents were out at work and her 12-year-old sister was on her way home after school. The victim called her mother - a boutique saleswoman - who then alerted police. The schoolgirl told investigators that she had seen the man wandering around the corridor when she returned home. She was later taken to Queen Mary Hospital for an examination. The sex attacker is believed to be 35 to 40, about 170cm tall and of medium build. He was wearing glasses with grey frames, a dark blue T-shirt, blue jeans and a pair of sports shoes. A 43-year-old man was arrested after officers conducted a door-to-door inquiry in another block of flats in the same estate about 4pm. The suspect, a construction site worker who is married with one son, was being held for questioning in Western police station last night. Mr Sheung said the suspect was likely to be released on bail pending further investigations. Detectives from Western district crime squad also seized closed-circuit TV tapes. Mr Sheung said police would study whether yesterday's case was linked to the five unsolved sex attacks committed in Western in 1999. A serial sex attacker who preys on girls in school uniforms is believed to have raped a 10-year-old girl and indecently assaulted four others. The victims were girls aged between 10 and 14 who were attacked on their way home, during lunchtime or after school. The attacks led to a warning from police to parents in Western not to let their young daughters out alone.