The U.S. Secret Service Wednesday confirmed that it has made several arrests in connection with a recent wave of debit card fraud that forced several banks and credit unions to reissue millions of cards over the past few months.

The arrests were part of a broader undercover Secret Service investigation known as "Operation Rolling Stone" that has so far resulted in the arrests of 21 people on charges related to online identity theft as well as credit and debit card fraud.

Seven of those arrests occurred yesterday in Florida, New York, Illinois, Pennsylvania, California and Washington, according to Secret Service spokesman Jonathan Cherry.

"Previous arrests occurred in a number of locations nationwide, with one arrest in the United Kingdom," he said.

According to Cherry, some of the 21 people arrested so far are linked to the recent debit card fraud wave, but he did not say how many.

"Rolling Stone is an active operation and in its initial stages [is] targeted at online criminal enterprises that threaten our financial infrastructure," Cherry said.

The arrests come amid a wave of debit card fraud resulting from a security breach involving a still undisclosed US retailer or retailers. The fraud resulting from the breach has so far forced many major banks, including Bank of America, Wells Fargo Bank and Washington Mutual Bank -- as well as numerous credit unions around the country -- to block transactions and reissue over 1 million cards.

Many of the compromised debit cards were being used fraudulently in several countries, including Romania, Russia, Spain and the U.K.