LONDON — Police on Tuesday arrested a “health-care professional” on suspicion of murdering eight babies and attempting to kill six other infants. The arrest is tied to “Operation Hummingbird,” an inquiry into the sudden and unexplained deaths of 17 babies at a top-tier public hospital in Britain.

The female suspect worked in the neonatal unit of the Countess of Chester Hospital, south of Liverpool.

Detectives were brought into the case after the mysterious deaths of 17 babies at the hospital between March 2015 and July 2016, alongside 15 “non-fatal collapses.”

“Asking the police to look into this was not something we did lightly, but we need to do everything we can to understand what has happened here and get the answers we and the families so desperately want,” said Ian Harvey, medical director at Countess of Chester Hospital.

“We are continuing to support Cheshire Police with their ongoing investigation,” he added in a statement, noting that the hospital supports the equivalent to a “Level 1 Special Care Baby Unit.”

“We are confident the unit is safe to continue in its current form,” Harvey said.

Police released few details about the ongoing investigation, which began in May 2017 after a spike in baby deaths at the hospital, but they said they are working alongside doctors and medical experts to understand the causes of death.

“This is an extremely difficult time for all the families, and it is important to remember that, at the heart of this, there are a number of bereaved families seeking answers as to what happened to their children,” said Cheshire Police Detective Inspector Paul Hughes, who is in charge of the investigation.

Hughes called the investigation “highly complex and very sensitive” and said his detective team was doing “everything we possibly can to try to establish in detail what has led to these baby deaths and collapses.”

He appealed to the public for any relevant information.