A member of staff at a mental health clinic in Heerlen, who was stabbed on its premises last week, has died of her injuries.

A 29-year local woman, who was arrested shortly after in connection with the incident, will now be facing charges of murder or manslaughter, Dutch media reported.

A police investigation at the time of the stabbing, in which the victim sustained serious injuries to one lung, found that the victim and the perpetrator knew each other in a “therapeutic setting”.

The 39-year-old victim had worked at the clinic, which is part of the Mondriaan group, for 20 years. “She was a spontaneous, enthusiastic colleague whose heart was in the job. She was small but feisty. We will miss her,” he colleagues said in a company document..

Why the woman attacked the member of staff is not known. Sources suggest a random attack but the public prosecution office declined to comment.

Some 30 to 40% of staff at psychiatric clinics experience violence from patients every year, research has shown.