NEW YORK (CNNMoney) -- Bank of America's online banking system went on the fritz for some users Tuesday, the second such incident this year.
Customers attempting to access the bank's online services were experiencing "intermittent service disruptions," according to Tara Burke, a spokeswoman for the bank.
The bank is working to restore the system to normal as soon as possible, Burke said. The bank's branches and ATM network are unaffected, she said.
In January, the bank experienced a similar problem, caused by an IT glitch.
Tuesday's service disruptions are the result of a routine update performed on the system over the weekend, and no personal personal banking data is at risk, Burke said.
But the outage is particularly ill-timed, hitting on the first of the month -- a day when many customers are scrambling to pay bills. Bank of America "will work with customers on an individual basis" to resolve any problems stemming from that, Burke said.
The problem kept Bank of America's Twitter account, @bofa_help, hopping all day, pumping out a steady stream of messages saying: "We are aware of the issue and are working to resolve it as fast as possible. Please accept our apologies."
Frank Murray, a Bank of America customer in Fort Myers, Fla., said he had trouble logging into his account for much of the day.
"It was off much of the afternoon, and unusually slow before that," Murray said.
Murray said attempts to access his account were met with a screen declaring there was an "outage." Later the message changed to an "upgrade."
Shares of Amazon have been on fire lately. Investors are bullish after the company's latest earnings. Even Warren Buffett is a big fan of Amazon CEO Jeff Bezos -- even though Berkshire Hathaway does not own Amazon stock. More
It's getting worse for Puerto Rico. The island defaulted on $422 million in bonds related to its Government Development Bank on Monday. Congress is currently debating an aid package for the island. More
Tech leaders Apple, Alphabet and Microsoft all disappointed Wall Street with their latest earnings reports. And that's dragged the Nasdaq back near correction territory. Is this the beginning of another huge pullback or an overreaction? More
In 1998, Ntsiki Biyela won a scholarship to study wine making. Now she's about to launch her own brand. More