LONDON (AP) _ Police investigating the suspicious deaths of five patients at a hospital in northern England said Friday that they had charged a 27-year-old nurse in the case.

Police and prosecutors say that Rebecca Leighton endangered the lives of patients at the Stepping Hill Hospital in the town of Stockport, near Manchester, by damaging saline bags, saline ampoules, and unspecified medical products.

Saline is the salt water solution used to deliver intravenous drugs or keep patients hydrated. Depending on how it's used it can be kept in clear plastic bags or smaller glass ampoules.

Authorities didn't say how the bags or ampoules had been tampered with in their statements Friday, but police have previously said that saline at the hospital had been spiked with insulin. Overdosing on insulin can lead to low blood sugar, which in extreme cases can lead to convulsions, coma or death.

Left unclear was how the nurse was alleged to have gone about sabotaging the bags or how she could have done so unnoticed. The alarm was raised last week after a high number of the hospital's patients suffered unexplained low blood sugar levels. Five deaths are being looked into by detectives, as is the condition of a sixth patient, an unidentified man in his 40s.

Although overshadowed by the scandal over phone hacking at Britain's now defunct News of the World tabloid, the hunt for what The Sun dubbed the ``saline serial killer'' has drawn considerable attention in Britain.

Police have said it was likely that more deaths would have to be investigated and prosecutors left open the possibility that more charges would be brought.

Greater Manchester Police said Friday that Leighton faced six counts of intentionally or recklessly endangering life. The police did not make clear whether each count related to separate patients, and in an email exchange said that they were not able to clarify the matter.

Leighton was due to appear in at Manchester Magistrates' Court on Saturday. If found guilty, she could face a life sentence.