Sony's PlayStation network remains offline after a hack attack on Christmas Eve. Microsoft Xbox is online, but service is limited for some apps. (Reuters)

Christmas turned into a frustrating day for many people eager to play games on new Xbox or PlayStation machines.

Online gaming services provided by Microsoft’s Xbox Live and Sony’s PlayStation Network were plagued by outages, and a hackers group called the Lizard Squad took responsibility for the problems via Twitter.

Both companies acknowledged the difficulties experienced by users on what is presumably a heavy day for online gaming by recipients of new game consoles. But it was difficult to determine how widespread the outages were. Microsoft declined to comment on the scope of the problem and whether it was the result of a hack. E-mails sent to numerous Sony officials were not answered.

Xbox Live posted this message on its status page about 3 p.m. Eastern time: “Can’t sign in to Xbox Live? Don’t worry! We’re working to get everything back to normal ASAP. We appreciate your patience. Check back in 30 minutes for a status update.”

Sony tweeted: “We are aware that there have been issues reported with PSN. Thanks for your patience as we investigate.”

Data on the Web site downdetector.com showed thousands of reports of problems with both services at various times beginning Wednesday evening. Media reports said the problems resulted from a distributed denial of service attack, one that overwhelms a network with useless traffic.

According to Vox.com, Lizard Squad brought down Sony’s PlayStation network with a similar attack in August, and Business Insider UK said the group took down PlayStation and Xbox at the beginning of December. It has claimed responsibility for disrupting other online gaming sites. The group also tweeted a bomb threat against a commercial flight carrying Sony Online Entertainment President John Smedley, forcing an emergency landing.

The group last week threatened to take down PlayStation and Xbox over Christmas, according to Business Insider UK.

Sony has suffered a series of online attacks this month. Hackers gained access to company online files, exposing sensitive e-mails and forcing the company to cancel the nationwide release of “The Interview,” a comedy about a fictional attempt by two journalists to assassinate North Korean leader Kim Jong Un. U.S. officials blamed North Korea for the attack, but a hacker group called Guardians of Peace, which may have connections to Lizard Squad, also claimed responsibility.

Sony instead released the movie online, via the Xbox network and in a limited number of theaters Thursday.