Gardaí have arrested five people and seized drugs worth almost €350,000 after a series of searches as part of Operation Tara.
Some €200,000 worth of cannabis was discovered following a raid on a house in Dundalk, Co Louth.
Cannabis worth €110,000 was obtained by gardaí in Swords, Co Dublin.
A further batch of cannabis worth €38,000 was seized after a follow-up search of a property in Blanchardstown, Dublin.
The five people remain in garda custody in Ballymun and Blanchardstown Garda Stations.
Following the operation, Assistant Commissioner Angela Willis said: "Tackling the supply of drugs to communities will continue to be a priority for Divisional Drug Units and all members of An Garda Síochána, working in partnership with local communities to keep people safe.
"This seizure of a substantial amount of illicit drugs along with paraphernalia utilised to facilitate its distribution is significant in that regard."