Two more premature babies who were in the neonatal intensive care unit at a New Jersey hospital died last week, bringing to three the number who have died after a bacterial outbreak at the facility in September, the state Health Department announced Tuesday.

The two babies, who were infected six weeks ago at University Hospital in Newark, died last week, but the New Jersey Department of Health said it was not notified of the deaths until Monday.

This prompted the health department to send an inspection team to the hospital Tuesday.

“A Department survey team is on-site today to investigate the hospital's internal notification policies, governance, and other factors that relate to reporting of deaths of cases during an ongoing outbreak,” health officials said. "As of yesterday, the hospital's own infection control program was not aware of the deaths when contacted."

The cause of death is unclear because the infants had other health problems related to their being premature, the health department said.

A total of four infants at the facility were exposed to Acinetobacter baumannii, a hospital-acquired infection. The first child died in late September.

The baby who survived was discharged from the hospital at the end of October, the health department said.

There have been no new cases in the unit since October, a hospital spokeswoman said.

State health officials ordered corrective steps at the hospital last month that included the hiring of a certified infection control practitioner.