The man, his daughter and sons, residents of village Shyamo under Taj Ganj police station, consumed poison on Thursday night.
A man and his daughter died while his two sons are battling for life after the family allegedly consumed poison at their residence in Uttar Pradesh's Agra district, the police said on Friday.
The man, Maan Singh, his daughter Archana (11), and sons Abhay and Roopesh, residents of village Shyamo under Taj Ganj police station, consumed poison on Thursday night, they said.
The family's neighbours saw the four lying on ground with white foam oozing out of their mouths and rushed them to the hospital, where Singh and Archana were declared brought dead, the police said.
Abhay and Roopesh are in a critical condition and undergoing treatment at a private nursing home, they said.
Mr Singh's wife had died a fortnight ago after a long illness and the family was depressed over it, they said.