RAUTAHAT: A youth, supposedly mentally retarded, on Sunday morning killed own mother and sister, in Dharmapur village of Rautahat. The youth in his early 20s, Nanda Kishor Yadav, from Dhanari Tole, Dharmapur-9, is on the run since the incident and police have launched a manhunt to nab him. DSP Rajendra Pokharel of Rautahat District Police Office said Ram Kali Devi Yadav (45) and Anita Kumari (14) were found dead on a cart near their peanut farm on the Bagmati riverbank. He had hit both with a spade, according to police. Both the bodies are on the cart still since the incident at around10:30 am, police added. The trio were heading to the farm to harvest the peanuts.