Bank of America's website was down for about an hour early Monday afternoon.

The isitdown.com website reported problems with B of A's online banking site starting shortly after 1 p.m. Eastern. By 2 p.m., 420 customers had written in to the website-monitoring site to say they were having difficulty with Bank of America's online and mobile banking; most said that when they logged in to the website and the bank's Android app, they were automatically logged out.

Shortly after 2 p.m., the bank said the problem was solved, and the website appeared to be working properly. It gave no official reason for the glitch.

During the outage, the bank tried to manage customers' concerns. The bank posted a message to its website homepage: "Online banking is temporarily unavailable. Thank you for your patience." A spokesman said that "some customers may be experiencing issues accessing online and mobile banking" and that B of A was "working quickly to resolve" the problem.

The bank posted the same message at its @BofA_Help Twitter page. However, about 45 minutes into the outage, tempers began to flare on Twitter. One customer wrote: "Today we learned exactly how much @BofA_Help cares about the peace of mind of their customers. (Answer: not at all.)" Another said, "Very unsettling knowing I can't access my online account."

Bank of America has 30 million online banking users and 15 million mobile banking users.