In a bizarre incident, a 19-year-old college student allegedly killed her mother and two younger sisters on Monday after the family opposed her love affair, police said.
The first-year degree student and daughter of a police head constable first hit her mother with a grinding stone and killed her on the spot at Gandhigramam in Karur district.
She then attacked and killed her younger sisters, aged four and nine, with a sharp-edged weapon, police said.
The accused also tried to burn the body of her mother, they said.
The incident was reported to police by her third sister, who was also attacked but managed to escape with head injuries.
The family members had prevented the accused from marrying her lover and this was presumed to be cause of the attack, the police said, adding that the teenager had been missing after the incident.
A case has been registered and searches are on.