Pic shows: Kristina Khachaturian Three teenage sisters have been arrested for stabbing their father to death and beating him with a hammer after he allegedly raped them for years. According to reports, Mikhail Khachaturian, 57, had raped his three daughters for several years and had threatened to kill them if they told anyone. Kristina Khachaturian, 17, Maria Khachaturian, 18, and Angelina Khachaturian, 19, reportedly attacked their father in their apartment in the Russian capital of Moscow. The man was sitting in an arm-chair and watching TV when the three sisters attacked him simultaneously, according to reports. Kristina reportedly attacked him with a knife stabbing him his chest and neck whilst Maria swung a hammer onto his head. And reports suggest Angelina helped her younger sisters by spraying pepper spray into her father's face. Khachaturian reportedly managed to fight back briefly, grabbing a knife lying on a table in the room and stabbing the elder sister Angelina in her arm before his other daughters managed to grab the knife off him. Bleeding Khachaturian tried to escape the apartment and managed to run out into the staircase of his block of flats, according to local media. But his daughters then caught up with him and they reportedly stabbed him and hit with the hammer till he stopped moving. The alarm was raised by neighbours who called the police. Cops came to the scene and reportedly discovered Khachaturian's dead body lying in a pool of blood. The three daughters were arrested with younger sisters Kristina and Maria being taken to custody whilst elder sister Angelina, who was stabbed by her father in her arm during the attack, was taken to hospital. A police spokesperson said: "All three suspects confessed to the crime. The investigation is ongoing." Reportedly Khachaturian had demanded that the sisters spend days cleaning their apartment and preparing food. Reports suggest he was often displeased with how they did the housework and p