The stabbing happened outside a bar in Belfast

His sisters were speaking for the first time since the 33-year-old father of two died after he was stabbed in Belfast on Sunday.

"His wee boys are the picture of him. You just look at them. Now they are not going to remember him," Mr McCartney's sister, Catherine, said on Thursday.

"They are robbed of one of the best daddies any children could have."

Mr McCartney, of Mountpottinger Road in east Belfast, was found unconscious in Cromac Street. He died later from his injuries.

The dead man's sisters, Paula, Gemma, Claire and Catherine, said he was a "protector".

We are pleased that the decent people of the Short Strand are supporting us... It is vital that we get to the bottom of this Robert McCartney's sisters

They said they had already lost a brother four years ago and that Robert's murder was "shattering" for his wife, Bridgene, his young sons and his wider family.

They said there was anger in the community.

"We are pleased the decent people of the Short Strand are supporting us," they said.

"If anybody knows anything, it is important that they come forward and give information. It is vital that we get to the bottom of this."

On Wednesday, police released three men, including a senior republican, who had been detained following the attack.

A fourth man who was being questioned about withholding information concerning the stabbing was released on Thursday.

It is understood police are treating the incident as a pub fight.

Violence

Several police officers were injured in disturbances which followed search operations in the Markets area in connection with the killing.

Officers were attacked with bricks, bottles and stones during trouble on Monday night.

There were further disturbances on Tuesday as officers were subjected to stone-throwing.

A car was set on fire close to the Markets area and several police vehicles were damaged.

Former mayor Alex Maskey of Sinn Fein said "heavy handed" police tactics had caused the trouble.