A woman suspected of murdering 13 patients in a Tuscan hospital in 2014 and 2015 by administering fatal doses of a blood-thinning drug has been arrested, Italian police announced on Thursday.
Italy's para-military police, the Carabinieri, detained Fausta Bonino, 56, late on Wednesday.
The woman dubbed as "the hospital ward killer" has been accused of committing multiple homicides while working as a nurse in the intensive care and anesthesia ward of a hospital in Piombino, a city on the Tuscan coast.
Police said the nurse's alleged victims aged between 61 and 88 had "various pathologies.” Investigators are scheduled to hold a press conference later on Thursday.
Investigators believe the victims, all seriously but not terminally ill, died as a result of being given strong doses of anticoagulant drugs used to prevent blood clotting, triggering internal bleeding.
Bonino was arrested after it was revealed she was the only staff member involved in every case of recent abnormal deaths, the AGI news agency reported.
"In the horror rankings we have reached a new peak of human misery," Health Minister Beatrice Lorenzin said in a statement.
"This latest episode shows once again the necessity of careful monitoring of the oldest and most fragile people when they trust their lives to health institutions," she added.
Bonino has been imprisoned pending formal charges.
Police said that the married mother of two grown-up children had been treated for depression.
Earlier this month, Daniela Poggiali, another nurse in Italy also accused of being a serial killer received a life sentence for killing a patient with a lethal injection of potassium.
Poggiali who is suspected of murdering dozens of other patients achieved global notoriety after it was discovered that she had taken 'selfies' next to recently deceased patients that she found "annoying."