Two men are being questioned over the seizure of 112,000 euro worth of heroin.
The drugs were found in a car and house as part of an ongoing investigation into the sale and supply of drugs in Dublin's south inner city.
The pair, who are both aged in their late teens, were arrested when their car was stopped and searched on the South Circular Road.
Gardai said a further quantity of heroin was discovered in a house during follow up searches.
"Both males are currently detained under Section 4 of the Criminal Justice Act, 1984, at Kevin Street, Garda station," a spokesman said.
"In total heroin with an estimated street value of 112,000 euro, pending analysis, was seized during today's operation."