Eight people were in Garda custody last night after credit card "cloning" equipment was seized in houses in Dublin.
Items recovered included credit cards and a scanner for copying and embossing cards.
Gardai arrested five men and three women, all Romanian nationals, during raids on houses in Dublin 7 and 8. They were questioned at Store Street garda station. A man and a woman were released without charge last night.
Two Romanian men arrested in a Garda Bureau of Fraud Investigation operation on O'Connell Street on Monday remained in custody.
The seizures are the latest in an ongoing Fraud Bureau investigation into credit card embezzlement by organised crime gangs from across the Mediterranean, North Africa and Middle East.
Traditionally overlooked by cartels specialising in credit card crime, Ireland has in recent years been targeted by sophisticated operations using state of the art forgery equipment.
Last May, gardai seized stolen credit cards and forging equipment from an industrial estate in Finglas, north Dublin.
Detectives believe criminals originally from north Africa had been "skimming" credit card numbers from several city centre restaurants over the previous 12 months and using the information to forge replica cards. It was the first credit card forgery operation uncovered in the Republic.
The bureau has been working closely with high street banks since the beginning of the year after reports that criminals were using "skimmed" ATM cards to withdraw large sums of cash.
Last year, a forged credit card was used to purchase goods worth £250,000 in the Far East.
It is estimated that credit card fraud amounted to nearly £2 million in 1999. The State has previously been targeted by west African-based criminals, particularly the Nigerian-based "419 Coalition", named after the country's fraud legislation.
Last night, gardai again appealed to the public to be vigilant. They warned against letting cards out of sight in shops and restaurants, as gang members swipe the cards and then copy the information.