Two of South Korea’s main broadcasters, KBS and MBN, and cable channel YTN, suffered outages on Wednesday as a suspected cyberattack caused massive network failures. Three banks and two insurance firms also reported being shut down at about 2pm local time, according to the Yonhap News Agency. Cyber-terrorism investigators were looking into the cause as the cyber-alert level was raised to 3; level 1 is the highest. Hundreds of computers at the networks were paralyzed, but they continued broadcasting normally, The New York Times said. Although a key presidential official told Yonhap that it has not yet been determined if North Korea was involved in the incident, the assumed cyberattacks come after Pyongyang’s recent threats against both the U.S and South Korea over joint military drills and new UN sanctions, supported by the latter, following the North’s February nuclear test. South Korea’s military also raised its state of readiness today in response. “We sent down teams to all affected sites. We are now assessing the situation. This incident is pretty massive and will take a few days to collect evidence,” a police official said, according to Reuters.