Of the nine, two were girls while the rest were boys, CMOH Malda, Dr Dilip Kumar Mondal said.
Some of the infants were a day old, the CMOH said, adding none of them were more than a week old.
He said families of three of the infants hailed from neighbouring South Dinajpur district while six of the families were from Malda district.
The CMOH said malnutrition, breathing difficulty or septicaemia were the cause of the deaths.
Last month, the hospital had reported 13 crib deaths.