A man is in a critical condition in hospital following a shooting in Dublin in the early hours of this morning in which three women were also injured.

The shooting took place at around 2.30am outside Hanlon's pub on the Old Cabra Road in the north of the city. 

A gunman shot a 28-year-old man in the head as he was on the footpath outside the pub.

Detectives say the gunman continued to fire indiscriminately as he made his way back to a dark-coloured BMW car parked nearby.

The gunman was then driven away towards Prussia Street.

The injured man was taken to the Mater Hospital, where he is in a critical condition.

Three women, aged 19, 28 and 33, were also shot. All three were hit in the legs.

The group had been attending a 21st party at the bar.

Two were taken to Connolly Hospital Blanchardstown and the other woman is being treated in St James's Hospital.

Their injuries are not thought to be life-threatening.

Gardaí believe at least two men were involved in the gun attack and are appealing for witnesses or anyone with information on the incident to contact them.

The scene at Hanlon's Corner was preserved for a forensic examination.

Gardaí said it is extremely fortunate that there were not multiple fatalities following the shooting.