Three men and a woman were tonight being questioned by detectives hunting thekillers of a Belfast man gunned down in front of his children.
As police investigated the murder of west Belfast man Mr Danny McGurk, forensicexperts were also examining weapons seized during planned raids at houses in thecity.
Mr McGurk (35) was shot dead at his Ross Road home in the Lower Falls area ofthe city following a row with dissident republican paramilitaries.
He opened the front door to his killers on Sunday, just hours after he took aknife and went searching for the men who viciously beat him days earlier.
Three Real IRA supporters are believed to have pumped up to five bullets intohis legs and chest.
The row flared after the father-of-six allegedly urinated outside the house ofa dissident republican in the area.
Police confirmed the three men and a woman were arrested during searches athouses in south and west Belfast as part of the murder probe.
A rifle, several handguns and a quantity of ammunition was also taken forexamination, a spokeswoman added.
Even though the Provisional IRA had no involvement in the killing, UlsterUnionist leader Mr David Trimble claimed Mr McGurk's murder arose out of theinstability surrounding Sinn Fein's refusal to back Northern Ireland's newpolice service.
But Sinn Fein chairman, Mr Mitchel McLaughlin, hit back at the UUPchief, accusing him of a cynical attempt at political point-scoring.
He added: "Mr Trimble also ignores loyalist violence emanating from withinhis own community.
"In the past number of years the various unionist paramilitary gangs havecarried out violent campaigns against Catholics and engaged in feuds with each other.
"During this time Mr Trimble and the UUP sat on their hands and failed todisplay the political leadership which was required."