Two men have been arrested over the murder of Belfast man Robert McCartney.
A spokeswoman for the PSNI said the two were also being questioned over the attempted murder of Brendan Devine and "surrounding circumstances".
Police refused to say where or when the men were arrested and what age they are.
Mr McCartney (33) was beaten and stabbed to death on January 30th last after a row with known republicans in a Belfast city centre bar close to his Short Strand home. His friend, Mr Devine (31), suffered severe stab wounds in the attack outside Magennis's Bar.
In February, the IRA issued a statement saying it had expelled three of its members over the killing, two of them senior figures.
In June, two men were remanded in custody charged in connection with the murder.
The attack has brought pressure on the IRA and Sinn Féin leaderships, with Mr McCartney's sisters and fiancée mounting a high profile campaign to bring the killers to justice.
They alleged witnesses have been intimidated by republicans attempting to thwart the police investigation.