Four more people have been arrested in connection with the murders of three men in Limerick city between April 2008 and April 2009.
Yesterday, five men were detained in connection with the murders of Shane Geoghegan, Roy Collins and James Cronin.
These men were released without charge this morning. A file is being prepared for Director of Public Prosecutions.
This morning, two men and two women were arrested in Limerick city in connection with the murders.
All of those arrested are aged in their 20s. They are being held at Roxboro Road, Henry Street and Mayorstone Garda Stations.
