The UN warned last week that famine in Gaza was "almost inevitable".
A senior UN aid official warned that at least 576,000 people across the Gaza Strip - one quarter of the population - faced catastrophic levels of food insecurity and one in six children under the age of two in the north were suffering from acute malnutrition.
And the regional director of the UN's children's agency, Unicef, said "the child deaths we feared are here, as malnutrition ravages the Gaza Strip".
"These tragic and horrific deaths are man-made, predictable and entirely preventable," Adele Khodr said in a statement on Sunday.