Citi Bank said Thursday that about 200,000 Citibank credit card customers in North America had their names, account numbers and email addresses stolen by hackers who broke into their website.

Citigroup said it discovered that account information for about 1 percent of its credit card customers had been viewed by hackers.

Citi has more than 21 million credit card customers in North America, according to its 2010 annual report.

Citi Bank Operations discovered the problem during routine monitoring and they are contacting those customers who were effected.

The bank said hackers weren’t able to gain access to social security numbers, birth dates, card expiration dates or card security codes. That kind of information often leads to identity theft, where cyber criminals empty out bank accounts and apply for multiple credit cards.

Citi customers could still be vulnerable other problems especially if details about their other bank accounts and financial information linked to them could be acquired using the email information and account numbers hackers stole.

Federal regulators have taken notice and are asking banks to improve security.”Both banks and regulators must remain vigilant,” said Sheila Bair, chair of the Federal Deposit Insurance Corporation. She said federal agencies, including the FDIC, are developing new rules to push banks to enhance online account access.