Four adult members among the deceased apparently administered a pesticide to the two children, aged four and two years, last night and consumed it themselves, the preliminary probe suggested.
The family was reportedly facing a serious financial problem.
The deceased were identified as Kasturi Janardhan, his wife K Chandrakala (both in mid-50s), their daughter-in-law K Prabhatha (in her 30s), her two children, and one of Janardhan's sons, K Ashok (26).
Suresh, the couple's elder son and Prabhatha's husband, were missing, said inspector Y Mugalaiah.
"As per the preliminary information, Suresh had borrowed money from several people and the family was facing a serious financial trouble because of this," the police officer told PTI over phone.
Further probe was underway, he added.
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