Five men and one woman were arrested today over the murder of a convicted drug dealer a year ago.
They are being questioned about the shooting of Gerard "Topper" Staunton in Wilton, Cork, last January.
The Real IRA claimed the killing at the time.
In a wave of dawn raids this morning, gardai detained six suspects at a number of premises and homes across the city.
One of the men is in his 20s, two are in their 30s, one is in his 40s, and one in his 50s. The woman is in her 20s.
They are being held under section 30 of the Offences against the State Act at Mayfield, Togher, Bridewell and Gurranabraher garda stations.
Gardai said the arrests were made as part of an ongoing intelligence-led operation into dissident republican activity and the murder on January 20 last year.
More than 60 gardai are involved.
Staunton was shot by a lone gunman as he went to get into his car outside his rented house on West Lawn, Sarsfield Road.