Sony chief executive officer Howard Stringer apologised to users of its PlayStation Network, breaking his silence on one of the biggest Internet security break-ins ever.

However, he failed to provide a date when services would resume.

Stringer's comments come after he faced criticism of his leadership since Sony revealed hackers had compromised the data of more than 100 million accounts. Kazuo Hirai, his likely successor, led a news conference and apology on Sunday.

Sony issued its first warning on the break-in a week after it detected a problem with the network on April 19, infuriating many PlayStation users around the world. Sony said it needed time to work out the extent of the damage.     

"I know some believe we should have notified our customers earlier than we did. It's a fair question," Stringer said in comments posted on Sony's US PlayStation blog.     

"I wish we could have gotten the answers we needed sooner, but forensic analysis is a complex, time-consuming process.
 Hackers, after all, do their best to cover their tracks, and it took some time for our experts to find those tracks and begin to identify what personal information had - or had not - been taken."     

Sony previously said it would offer some free content, including 30 days of free membership to a premium service to existing users and in some regions pay credit card-renewal fees.

"I know this has been a frustrating time for all of you,"  Stringer said. "To date, there is no confirmed evidence any credit card or personal information has been misused, and we continue to monitor the situation closely," he said in a statement dated May 5.

Stringer said Sony would restore network services "in the coming days", but gave no date. 

"That's all well and good, but when exactly is the PSN going to be back up? "Coming Days" could be tomorrow or it could be weeks from now," a user called Morac said on the PlayStation blog.

Stringer also said the company had launched a data theft insurance policy for its PlayStation Network and Qriocity users.

Sony's revelation of a second Internet breach on Monday came just a day after it said measures had been put in place to avert another cyberattack like that which hit its PlayStation Network, leading to the theft of information on 77 million user accounts.

The Internet breaches sparked thousands of comments on the official PlayStation fan page on Facebook, some of them from users who said they would switch to Microsoft's Xbox Live games network.

One analyst said security concerns could weigh on sales of Sony gadgets and hurt growth prospects for its network services. - Reuters