(Reuters) - Bank of America Corp, the No. 2 U.S. bank by assets, on Saturday said its mobile and online banking systems were working again after crashing on Friday.

Customers who attempted to log onto the website on Friday received a message that said the site was "temporarily unavailable." An internal systems issue caused the problems, a person familiar with the situation told Reuters.

Bank of America says it has 30 million active online banking customers.

(Reporting By Rick Rothacker in Charlotte, N.C.; editing by Gunna Dickson)