Two men are being questioned following the seizure of €600,000 worth of mephedrone and herbal cannabis.
The men, one Irish and one Brazilian, are currently being held at Kevin Street Garda Station.
The mephedrone was imported through Dublin Airport in a parcel consigned from China.
Customs, the Garda National Drugs Unit and the Kevin Street Garda Drugs Unit were all involved in the operation.
In a separate operation, a man in his 20s was arrested after mephadrone and cocaine with a street value of €22,000 was recovered following a search of a house in the Whitestown area of Blanchardstown.
He is being held at Blanchardstown Garda Station where he can be questioned for up to 24 hours
