Lance Whitney/CNET

South Korean news agencies and security officials say that cybercriminals have leaked the personal data of members of the U.S. military.

On Tuesday, South Korea suffered its latest round of cyberattacks on the day that marked the beginning of the Korean war 63 years ago. The South Korean Science Ministry confirmed that multiple government and private sites were affected. The Central News Agency, party newspaper Rodong Sinmun, national airline Air Koryo, and the presidential Blue House site were among those that experienced service outages.

Following the attack, Reuters reported that the cybercriminals involved claim to have publicly released the personal details of over 2 million South Korean ruling-party members and 40,000 U.S. troops. Some of the 28,500 U.S. troops posted in South Korea may have had personal information stolen.

"We have seen the sites where the details were posted and clips that supposedly capture the process of hacking into web sites," an unnamed official from South Korean online security firm NSHC told the publication.

The legitimacy of the leaked data has not been verified.

The South Korean government is further investigating the cyberattack. Although no suspects were named, the methods used were similar to past attempts by North Korea to hack into important sites, and some of the replaced home pages on vulnerable sites praised North Korean leader Kim Jong-Un.

North Korea has previously denied involvement in cybercrime, and last week the country's state-run newspaper Minju Joson jumped on the Edward Snowden fracas to accuse the United States of being "a kingpin of human rights abuses" and to say that both foreign nationals and American citizens are "subject to the espionage that has been applied indiscriminately by the U.S. intelligence institution."