A female hospital worker in Britain has been arrested in connection with the suspicious deaths of four children.
Thames Valley Police arrested the unidentified member of staff at Wexham Park Hospital at Slough, Berkshire, last night.
Police were called in after consultant paediatricians raised the alarm about the unusually high death rate on the children's medical ward 24 between July last year and this month.
A spokeswoman for the Heatherwood and Wexham Park Hospitals Trust said no exceptional features emerged in the routine review of the deaths and post-mortems proved inconclusive. A helpline is being set up for worried relatives.
The woman has been questioned and bailed.
She added: "However, when all of the cases were reviewed together, the fact that there were four such deaths contrasted with the annual average of two or three.
"The trust has therefore taken the concerns very seriously and brought in Thames Valley Police."
A police spokeswoman said: "Police were called in by the hospital on Monday evening after consultant paediatricians at Wexham Park expressed concerns to the management about the unexpected deaths on the children's medical ward."
A family liaison officer has been brought in to keep bereaved families up to date with the progress of the investigation.
PA