Local residents of B N Road in the Natunpara area of Uttarpara heard screams from a three-storey building this evening and when they approached the house, they saw a youth jumping off from the terrace and trying to flee.
As the youth was injured, the residents caught hold of him and informed the police.
When the police entered the building, they found a resident of the house, Kaberi Sen (52), with her throat slit and lying in a pool of blood. Her mother-in-law Geeta Sen (71), was also found lying on the terrace with her throat slit. Two other members of the family were found in one of the rooms, injured.
"Since the youth had jumped from a considerable height, he fractured his leg and there were some other injuries on him," said a police officer.
The youth was under treatment and has been arrested, the officer said adding, investigations were on.