Sony is slowly bringing its PlayStation Network back into service as it continues to evaluate the impact of a security breach that affected over 100 million users.

The Japanese tech giant announced Sunday that users in the United States and Europe would be able to again use online gaming, chat and music-streaming services associated with the network. Full services are due to be restored by the end of May.

Sony spokesperson Satoshi Fukuoka said a phased restoration of the company's Qriocity movie and music services, which run on the same server as the PlayStation Network, would also begin Sunday.

Limited PlayStation Network services are due to resume Sunday in Canada, Australia, New Zealand and in the Middle East. Sony said it would start restoring the service for its customers in Asia soon.

When active, the PlayStation Network helps link gamers around the world in live play.

But the network was shut down April 20, after Sony discovered a hacker attack that put more than 100 million online accounts at risk.

After the attack, Sony warned its customers that their personal information may have been stolen. However, the company has so far not received any reports of the stolen information being used illegally.

The chief of PlayStation's video game unit, Kazuo Hirai, said in a statement that the company has since beefed up its efforts to protect its customers' personal data.

For the immediate future, customers will not be able to buy video games or other content using credit cards while Sony finishes testing new security measures.

"While we understand the importance of getting our services back online, we did not rush to do so at the expense of extensively and aggressively testing our enhanced security measures," said Hirai.

The company continues to probe the attack on its PlayStation Network which was first detected on April 19, but not made public for another week.

Sony is facing lawsuits in Canada and the U.S. as a result of the April breach, and the company has been criticized for not notifying its customers about the problem quickly enough.

With files from The Associated Press