The Police Service of Northern Ireland, working with the gardaí, seized cannabis with a street value of €500,000 in the North yesterday.
Two men were arrested in Lisburn and Armagh and a third man was arrested in Monaghan last night, as part of the planned operation.
The PSNI’s organised crime branch said it had worked with the Garda National Drugs Unit.
Police said a large amount of cash was also seized during the raids.
The PSNI said it had arrested a 41-year-old man in Lisburn outside Belfast and a 27-year-old man in Armagh city. It said that the drugs and cash were seized in the raids that took place north of the Border.
The Garda drugs unit was assisted by the force’s Monaghan drugs unit, where the third man was arrested by gardaí.
