An E. coli outbreak has been discovered at a south-east London hospital.
Ten cases of the bacteria have been identified on the neonatal ward at the Queen Elizabeth Hospital in Woolwich.
As a precaution the ward has been closed to outside admissions and special procedures have been implemented to stop it spreading.
The hospital said 10 cases of resistant E. coli bacteria had been detected and tests were being carried out to identify how it got into the unit.
South London Hospitals NHS Trust said none of the babies were clinically affected by the bacteria, which is only harmful once in the bloodstream.
Babies who appear to carry the bacteria have been isolated and some of those affected have already been allowed home, a spokesman said.
He said: "The Trust is working with the Health Protection Agency to ensure that the correct measures are being taken to prevent any further spread of the infection and we can assure our patients that the rest of the hospital is not affected."
The Trust's other two neonatal units at the Princess Royal Bromley and Queen Mary's Sidcup remain open.