DANVILLE, Pa. - A central Pennsylvania hospital said it has discovered the source of bacteria that killed three premature infants in its care.

Geisinger Medical Center in Danville said the process it was using to prepare donor breast milk led to the outbreak in the neonatal intensive care unit that infected eight premature infants.

Officials said experts traced the bacteria to equipment used to measure and administer breast milk.

They said the milk was not the source of the exposure.