North Korea's major websites were normalized after having trouble connecting on Tuesday amid a cyber stand-off with the US over the hacking of Sony Pictures Entertainment, South Korean media reported.
The Websites of the North's official mouthpieces, such as the Korean Central News Agency and the Rodong Sinmun newspaper, were disconnected from the Internet from early morning to 11 a.m. (0200 GMT), according to Seoul's public broadcaster KBS.
The North's propaganda Website Uriminzokkiri has also shown instability with connection on the day before getting back on line.
A South Korean government official confirmed the connection problems with the North Korean Websites but added that the government is yet to determine whether it was caused by a cyberattack.
It is highly unusual for Pyongyang's main websites to suffer such troubles at the same time, Yonhap News Agency reported. Some observers in Seoul have raised the possibility of a retaliatory attack by civilian hackers on the North or the involvement of the US government.
Washington believes that North Korea was responsible for the recent hacking of Sony Pictures Entertainment, the producer of a comedy film about a plot to assassinate the North Korean leader Kim Jong-un. US President Barack Obama vowed a "proportional" response to what he called "cyber vandalism."