An international hacking group that had previously claimed it hacked North Korean Web sites said on Sunday it launched more cyber attacks into about a dozen sites based in the communist state.

The group called "Anonymous" said on its Twitter account (@AnonyOpsKorea) that it successfully hacked the Web site for the North Korean radio station called "Voice of Korea." Anonymous released the photo of the opening page of the Web site, with the "VOK" logo at the top right-hand corner and the word "Hacked" positioned at center.

Anonymous also said it targeted www.uriminzokkiri.com, the North's propaganda site, and the homepage for the state-run Korean Central News Agency, but didn't say whether these attacks were successful.

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

In April, Anonymous released the list of some 9,000 subscribers to Uriminzokkiri, including about 2,000 members using e-mail addresses provided by South Korean portal sites, companies and newspapers.

Anonymous also claimed in April to have hacked into the network at Korea Exchange Bank (KEB) and released the list of people that it said were the bank's customers. KEB later rejected Anonymous' claim, saying the personal information on the hacking group's list didn't match details of its clients. (Yonhap News)