Four men are being questioned after detectives busted a suspected cannabis-growing operation.
Nearly €500,000 worth of the drug was seized during a raid on a "grow house" in Baltinglass, Co Wicklow, and a follow-up search in Dublin.
Two men, aged 23 and 30, were arrested when gardai uncovered the makeshift cannabis factory and plants with an estimated street value of €144,000 around midday yesterday.
In follow-up searches, another two men, aged 25 and 36, were detained in Wicklow and west Dublin.
More herbal cannabis, believed to have a street value of €312,000, was also seized.
All four men are being held at Garda stations in Baltinglass, Carlow, and Kevin Street, Dublin.
They are being questioned under section two of the Drug Trafficking Act.
The raids were carried out by gardai in Baltinglass, the Tallaght Drugs Unit and the Kevin Street Drugs Unit, as part of Operation Nitrogen.
The Garda National Drugs Unit is coordinating the operation.
The cannabis has been sent for forensic analysis.