30-year-old Archana was found hanging while her two daughters, aged 10 and eight, were found dead, allegedly due to poisoning, inside the house, police said, adding the woman's husband was working abroad.
In the adjacent house, their neighbour Ratheesh, his wife and three-year-old daughter were also found dead this morning, they said.
Investigation was on to ascertain whether there was any link to the deaths and also to find the motive behind the killings, which are being suspected as suicides, police said.