Three of eight infants who acquired a bacterial infection in the neonatal intensive care unit at Geisinger Medical Center near Danville, Pennsylvania, have died.

Hospital officials, who are working to determine the specific source of the waterborne infection, confirmed Monday all eight premature infants were treated recently for a pseudomonas bacterial infection.

Although pseudomonas bacteria cause one of the most common hospital-acquired infections, Geisinger officials said in a statement the deaths "may have been a result of the infection complicating their already vulnerable state due to extreme prematurity."

Specifically, Dr. Frank Maffei, chair of pediatrics for Geisinger, told WNEP seven of the eight sickened infants were born before 27 weeks.

Four of the other five affected infants are "doing well" following successful treatment, and the fifth is "responding positively" to continued antibiotic treatment, according to the hospital's statement.

Dr. Mark Shelley, director of infection prevention at Geisinger, told ABC News the center found no evidence of the bacteria throughout the hospital.

"It's really too soon to say exactly where the organism is coming from," Shelley told the network, though hospital officials have confirmed the reported infections were confined exclusively to the NICU.

In addition to working in tandem with the Pennsylvania Department of Health and the Centers for Disease Control and Prevention to eliminate the bacteria and prevent additional cases, Shelley told ABC News the medical center has taken several proactive steps such as extra cleaning, the addition of tap filters and tweaked internal protocols.

Meanwhile, Geisinger is diverting infants born at less than 32 weeks and moms who may deliver that early to other hospitals, WNEP reported.

"We express our deepest sympathies and provide our full support to the families and loved ones who have been affected," the hospital's statement continued, adding, "We will continue our meticulous and comprehensive infection control practices to reduce the risk of any infection in any infant, and we remain committed to providing the highest level of family-centered neonatal care for our families and babies."

Read the medical center's full NICU update here.