Dr. Ahmed al-Rudaini, a spokesman for the Iraqi Ministry of Health, said the 11 infants who died were being treated at a ward for premature babies at Yarmouk Hospital, in western Baghdad.
More than 25 people, babies and women, suffered burns or smoke inhalation and were evacuated to other hospitals. Several of the mothers were awaiting cesarean sections.
Officials said the episode, which happened shortly after midnight, began when an oxygen bottle exploded in a corridor, setting off an electrical fire and creating scenes of panic.
The hospital is supported by the government, and patients pay little or nothing, even for major surgeries.