A 19-year-old constructionworker was arrested under the Protection of Children from Sexual Offences (POCSO) Act on Monday on charges of impregnating a teenage girl student on the pretext of marrying her.According to police, the worker and the 15-year-old girl were staying at Koundanpalayam in the city and in a relationship.However, when he refused to marry her, the girl narrated the incident to her mother.Based on the complaint, police arrested the worker.He has been remanded to judicial custody.In another case, three youths hailing from Uttar Pradesh, all construction workers, were arrested when they allegedly tried to sexually abuse a 12-year old girl at Podanur here, police said.The trio noticed that the girl was alone at home and tried to molest her on Sunday evening.Hearing her screams, the neighbours rescued the girl and handed the three youths to police after thrashing them.They have been remanded to judicial custody.