The republican group which last week murdered north Belfast man Kevin Kearney has given two of his friends 48 hours to leave the country or be killed.
Just hours before Mr Kearney's funeral, armed and masked members of the group calling itself the 'IRA' entered a social club in Ardoyne and publicly read out the threat.
Mr Kearney's funeral mass was held at Holy Family Church on the Limestone Road yesterday.
Father Paul Strain began his homily by saying: "Many words have been said about Kevin good and bad, true and not so true.
"Ultimately the only word that really matters is the final word of God."
A 45-year-old man was arrested in north Belfast by detectives investigating the murder yesterday afternoon.
Mr Kearney's body was recovered from a lake in Alexandra Park last Wednesday after he was shot dead in broad daylight. He had returned from dropping his daughter at school and had taken the dogs for a walk in the nearby park. But when his two dogs returned to his home on Dunmore Road in north Belfast without him, his family raised the alarm.
In a statement last week claiming responsibility for Mr Kearney's murder, the IRA alleged he had been involved in "the supply and distribution of class A and class B drugs".
In their latest threat early yesterday, the republican group named two associates of the murdered man and ordered them to cease their "activities" and leave the country within 48 hours.
"Failure to respect this notice will result in a swift response from the IRA," the statement said.
Friends of Mr Kearney's have claimed that dissident republicans are taxing drug dealers and that the father of four was murdered for refusing to pay the IRA extortion money.
The masked IRA men ordered what it called a "criminal network" of drug-dealers to disband.
"You are aware of the consequences of your activities and you will receive no further warnings," they said.
The PSNI said it was investigating reports that several armed and masked men entered a bar in north Belfast early yesterday.
The masked republican paramilitaries also threatened an unnamed member of Mr Kearney's family whom they claimed had clashed with them over the murder.
They said "all threats shall be met with absolute resolve" and "the IRA will protect our volunteers at all costs".
As Mr Kearney was being buried in Milltown cemetery, parties at Stormont united in their condemnation of the murder.
Justice Minister David Ford said: "This Assembly is where the people of Northern Ireland decide their future, not thugs on the street and that has to be the message that goes out from all of us together."
Sinn Fein's Gerry Kelly (left) said: "Pseudo-republican groups use some sort of veneer to hide the fact that they are involved in drug dealing, extortion, and taking money or backhanders from drug dealers.
"They then decide that they should kill others whom they accuse of the same thing."
"I've just been comforting the family in the after shock of it and I was at the wake last night. They are devastated, it's an awful feeling. They were sitting with photographs last night going over memories, it's just tragic."
Father Gary Donegan from Holy Cross Parish, Ardoyne