The California Department of Motor Vehicles Saturday said there is no evidence showing a direct breach of its computer system but it would open an investigation "out of an abundance of caution."
Earlier Saturday, security blogger Brian Krebs reported that banks in California and elsewhere were alerted by MasterCard about compromised cards that had all been used for online transactions at the California DMV.
The agency said it would pursue its investigation in conjunction with state and federal law enforcement.
"In its investigation, the department is performing a forensic review of its systems and seeking information regarding any potential breach from both the external vendor that processes the DMV's credit card transactions and the credit card companies themselves," read the statement issued by spokesman Armando Botello.
MasterCard, meanwhile, said earlier that it was “aware of and investigating” reports of a potential breech, company spokesman Seth Eisen told the Los Angeles Times.
The breach only involved online transactions, and not those made at California DMV physical locations, according to Krebs' report.
The DMV's statement added: "We will immediately notify any affected DMV customers as quickly as possible if we find any issue. DMV customers are also encouraged to closely monitor their credit card statements and transactions for any fraudulent or unusual activity and report it to their credit card company immediately."