Police in Belfast have launched a murder inquiry following the death in hospital of 65-year-old Harry Holland, who was stabbed in the west of the city on Tuesday night.
Mr Holland had been on a life support machine since he was stabbed with a screwdriver near his home in the Norfolk Drive area, and sustained serious head injuries.
The PSNI officer leading the investigation, Detective Chief Inspector Glen Wright, said two males aged 17 and two females aged 15 were arrested yesterday morning in connection with the attack and are being questioned at the serious crime suite in Antrim police station.
He described what happened as a horrendous incident and appealed for more information from the public.
The Lord Mayor of Belfast, Jim Rodgers, said people in the city were horrified and stunned at the death of Mr Holland.
He described him as a hard working man, a husband, father and grandfather who was well known and respected in the local community.
Mr Rodgers also called on parents of young people to lead by example and local agencies to pull together in an attempt to stamp out what he said was the type of horrendous behaviour that had led to the death of Mr Holland.
The Sinn Féin President, Gerry Adams, described it as a brutal and savage attack and appealed for anyone with information to make it available to the police.
Local people have described Mr Holland, who ran a greengrocer shop, as a gentleman who always worked hard for the community, young and old.
