Haryana police on Saturday evening arrested a 19-year-old girl for murdering seven of her family members, including her parents and brother, in connivance with her 20-year-old boyfriend.
Seven members of a retired teacher's family including his son and two daughters-in-law were found murdered in their house in Kabulpura village near this Haryana town, some 70 km from New Delhi, on Tuesday morning.
The victims had strangulation marks on their necks.
"We have arrested Sonam and her lover Naveen Kumar. Sonam mixed some intoxicant in the flour before the dinner Monday night. After eating the chapattis made from it, all the family members fell unconscious," Rohtak Superintendent of Police Anil Kumar Rao told IANS.
He said Sonam then called Naveen, who lives in the neighbourhood, and both of them killed the seven people by strangulating them.
The bodies were found by the teacher - Sonam's grandfather - who lives nearby, when no one came to give him his morning tea. The village is about 20 km from Rohtak.
The victims included the teacher's four grandchildren. His other son, who is in the army, was away when the crime was committed.