A widespread computer attack has hit several US government agencies while some
South Korean government websites also appear to be affected.
The US Treasury Department, Secret Service, Federal Trade Commission and
Transportation Department were all hit by the attack that started on July 4.
In South Korea, the presidential Blue House and Defence Ministry, National
Assembly appear to have been hit.
US officials have not released details of the attack.
Ben Rushlo, head of internet technologies at web performance firm Keynote
Systems described it as a "massive outage".
Amy Kudwa, a spokeswoman for the Department of Homeland Security said the
body's US Computer Emergency Readiness Team told federal departments about the
issue and of steps "to mitigate against such attacks".
Recently the US homeland security secretary Janet Napolitano told the BBC that
protecting against virtual attacks was a matter of "great concern" and
something the US was "moving forward on with great alacrity".
The attacks in South Korea seemed to be connected to the attack of US
government services, said Ahn Jeong-eun, a spokesperson at Korea's Information
Security Agency.
North Korea's Yonhap News Agency is reporting that North Korea may be behind
Tuesday's cyber attack.