Wells Fargo & Co. was working to protect its website Wednesday after being under cyberattack a day earlier.

"We apologize to customers who may be experiencing intermittent access issues to wellsfargo.com and online banking," the San Francisco-based bank said in an e-mailed statement. "We are working to quickly resolve this issue."

The bank said customers can still access their accounts through ATMs, stores and by phone.

The Wall Street Journal reported that 220 customers filed complaints with the bank Tuesday. A web-based site-tracking service called sitedown.co also reported many complaints, including that customers could not log in and that pages would not load.

The bank was not immediately available to respond to questions, though its main web pages appeared to be loading properly early Wednesday.

It was not clear who was behind the attack, although a group calling itself the "Cyber fighters of Izz ad-din Al qassam" announced last week on the web that it was behind earlier bank attacks in retaliation for the anti-Muslim movie produced in the United States.

David Shaffer ¶• 612-673-7090