The computer networks of major South Korean banks and broadcasters have gone down and police are investigating the possibility of a cyberattack.
South Korean Internet service provider LG Uplus said on March 20 it believed its network had been hacked.
A National Police Agency spokesman told the AFP news agency its cyber team is investigating the reports of a concerted attack.
The Yonhap news agency is reporting that computer networks were paralyzed at two banks and three broadcasters, KBS, MBC, and YTN.
The disruptions come days after North Korea accused the United States and South Korea of carrying out cyberattacks on websites in the North.
Pyongyang is thought to be responsible for two cyberattacks in 2009 and 2011 that hit South Korean government agencies and financial institutions.
Based on reporting by AP, Reuters, and AFP