Two security men are being treated for gunshot wounds after they were shot outside St James's Hospital in Dublin.
The incident happened at around 4.30am this morning close to the Rialto exit.
Gardaí are investigating the possibility that a burnt out vehicle found in Crumlin may be linked to the shooting.
The green vehicle was found at Aughavannagh Road in the early hours of this morning a short time after two security guards were shot.
The security guards are recovering in hospital this evening after undergoing surgery.
One man sustained a gunshot wound to the arm. The other also sustained a gunshot wound.
The men, who are both 28 years old, work for a security firm contracted by St James's Hospital to provide security for patients and nursing staff.
It is believed two masked men both armed with weapons were involved in the shooting. The attackers were wearing balaclavas and dark clothing.
It is not yet known if both weapons were fired in the attack.
A spokesman for the hospital said the shooting has not affected patient services and that everything is operating as normal.
The two security men are both members of the SIPTU trade union, which said the incident highlighted the dangers faced by security personnel in protecting others.