A senior doctor at a Limerick psychiatric hospital was fighting for his life tonight after being stabbed by a patient.
Another senior medic, a female psychologist, was also said to have suffered multiple stab wounds in the attack at St Anne's Day Psychiatric Hospital in the city. She was understood to be in a stable condition.
Gardaí said a man in his 30s was arrested at the scene shortly after 2.45pm.
The HSE-run centre treats people for a range of conditions, including addiction, anxiety, detox and depression, and gives psychiatric assessments.
It is believed that the psychiatrist worked with former prisoners as well as those in the community.
Staff at the hospital were said to be in a state of shock and unable to speak about exactly what had happened.
Health chiefs said they have brought in counsellors and other support services to help the workers.
Two separate investigations have already been launched by both the gardaí and the HSE.
"Gardai are at the scene and the families of the injured staff, a man and a woman, have been informed," said a HSE spokesman.
"The HSE is co-operating with Garda inquiries and the incident has also been notified to the mental health inspectorate.
"Counselling and other appropriate supports have been put in place for staff working at the day hospital."
A Garda spokesman said: "A man in his early 30s is in custody at Roxboro Road Garda Station, detained under Section 4 of the Criminal Justice Act, having been arrested at the scene."