Four people are being questioned in connection with a serious assault in Dublin over the weekend.

A man in his 20s sustained serious head injuries in the attack and is in a critical condition in Beaumont Hospital.

He was walking along Lamb Alley at around 2am on Sunday morning.

A window on a parked car was broken and the man was seen trying to steal items from the car.

Two other men came upon him and attacked him, beating him severely and kicking him in the head.

He was taken to St James's Hospital but transferred to Beaumont Hospital, which has a specialist neurological unit.

Gardaí arrested two men this morning on suspicion of assault causing serious harm. Two women were arrested on suspicion of withholding information.

The four are being questioned at Pearse Street, Irishtown, Kevin Street and Kilmainham garda stations.

Gardaí have also issued an appeal for anyone who was in the area around Lamb Alley at the time, in particular taxi drivers, to contact them.