Over €1 million worth of cannabis was seized following two separate searches of properties in Co Kilkenny and Co Galway on Monday, gardaí said.
In Kilcolgan, Co Galway, gardaí recovered over €950,000 worth of suspected cannabis plants during the search of a "sophisticated growhouse" within a property.
Three people, a woman in her 30s and two men in their 40s, were arrested at the scene. They remain detained at the North Western HQ under the provisions of Section 2 of the Criminal Justice (Drug Trafficking) Act, 1996.
The search, part of Operation Tara, was carried out by gardaí connected to Galway Garda station and the Galway Divisional Drugs Unit shortly after 3:30pm on Monday.
Speaking on Monday about this seizure, Chief Superintendent Gerard Roche in Galway said: "This is a significant blow to those trafficking illegal drugs in the Galway Garda Division and we will continue to tackle organised crime and drug dealers in County Galway".
Meanwhile, in Co Kilkenny, a man in his 20s was arrested and charged after a seizure of approximately 7.2 kilograms of cannabis. The seizure had a street value of €114,800, gardaí said.
The man is suspected of being involved with an organised crime group operating in the South East of the country, the force said. He was due to appear before Kilkenny District Court on Tuesday morning.
The search was conducted in a joint operation between customs, the Garda National Drugs & Organised Crime Bureau, and the Kilkenny District Detective Unit/Drugs Unit.