Two premature babies have died after an outbreak of a rare infection in a hospital ward.
The two infants, who were both born before 28 weeks, died after contracting the infection at University Hospital of North Staffordshire NHS Trust.
The babies were being treated in the neonatal intensive care unit of the hospital, in Stoke, in July.
Five other children were isolated after it was found they were carrying the Serratia marcescens infection.
A hospital spokesman said the children were not unwell.
Serratia marcescens causes urinary tract, wound and bloodstream infections, which tend to be associated with critical care units.
Chief executive of the trust Julia Bridgewater said: "The trust identified an infection in our neonatal intensive care unit (NICU) in July, Serratia marcescens, that can affect babies born extremely premature.
"Sadly two babies who died, both born before 28 weeks, had this uncommon infection, and post-mortems confirmed Serratia marcescens as the cause of death. The families of the two babies were informed at the time of this infection.
"The trust would like to offer its sincere condolences to those families who have lost a baby."
Jeorge Orendi, consultant microbiologist, said: "As a precaution the trust temporarily closed NICU to new admissions and the five other babies who were carrying the organism, but were not unwell, were isolated.
"One of those five babies continues to be treated on the unit for other conditions and will remain here at University Hospital in isolation until they are well enough to go home.
"All the families with babies on the neonatal intensive care unit at the time that the infection was identified were kept fully informed.
"Parents of babies which have already been discharged have no need to worry."
Earlier this year, Professor Dame Sally Davies, the Government's principal medical adviser, issued guidance to special care units in England on dealing with different infection - pseudomonas bacteria - after a number of babies died in Northern Ireland.
Prof Davies said it is important that the NHS takes all necessary steps to minimise the risk of infection.