North and South have fired claims of cyberattacks at each other recently. Last month computers froze at six major South Korean companies — three banks and three television networks — and North Korea's Internet shut down.
Meanwhile, the website for the U.S. forces stationed in South Korea has been closed since Tuesday and their public affairs office said Friday that the problem does not have to do with any hacking.
"Initial assessments indicate it is the result of an internal server issue," it said on the website without elaboration.
AP writers Sam Kim in Seoul, Raphael Satter in London and Charles Hutzler in Beijing contributed to this report.
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