As early as Monday night, some visitors to Yahoo Photos and Yahoo Briefcase were greeted with a message saying, "The Web site might be experiencing technical difficulties."
A reader reported the outage to CNET News.com early Tuesday. As of midmorning, both sites remained inaccessible to some visitors.
"As of last night, Yahoo Photos and Briefcase were inaccessible to a small percentage of users due to software-related issues," a Yahoo representative said Tuesday. "We have identified the issue and corrected it."
The representative added that no user data was lost during the outage.
The outage is the latest in a series of incidents that have affected the accessibility of Yahoo's Web-based services. Last week, a software glitch caused a 45-minute outage that affected areas including its home page, Yahoo Mail and its My Yahoo personalization service.
Two weeks earlier, Yahoo's e-mail discussion list community Yahoo Groups also suffered from an outage that lasted nearly a day and prevented millions of people from receiving their e-mail. Yahoo blamed the problem on a hardware glitch.