Doctors and nurses told HRW "that many of their patients have died from preventable diseases and infections, and healable wounds, due to dehydration and the unavailability of water".
One emergency room nurse cited in the report said they were forced to decide "not to resuscitate children who were severely malnourished and dehydrated".
The rights group called on the international community to "take all measures within their power to prevent genocide by Israeli authorities in Gaza".
That included "discontinuing any military assistance and arms sales or transfers, imposing targeted sanctions, and reviewing bilateral deals and diplomatic relations".