The Health Service Execute has had to temporality shut down its IT system after a major cyber attack.
HSE CEO Paul Reid described the attack as "quite sophisticated and very targeted".
The Covid vaccination programme has not been affected.
In a statement, the HSE said: "There is a significant ransomware attack on the HSE IT systems.
"We have taken the precaution of shutting down all our IT systems in order to protect them from this attack and to allow us fully assess the situation with our own security partners.
"We apologise for inconvenience caused to patients and to the public and will give further information as it becomes available."
The Rotunda Hospital says it has cancelled most of its appointments for today except for emergencies.
Pic: Damien Storan
