The international hacking group Anonymous claims it hacked into three key North Korean Web sites as a prelude to a barrage of cyber attacks it's planning on June 25th.

Anonymous said on its Twitter account (@AnonyOpsKorea) that it successfully hacked the site for the North Korean radio station "Voice of Korea" and also targeted the state-run Korean Central News Agency homepage and the portal of North Korea's propaganda site, Uriminzokkiri.

It said Sunday's attacks were part of only a small operation and that they will launch a "very huge" operation on June 25th, the anniversary of the Korean War.