South Korea raises cyber alert level after North Korean bomb test

South Korea’s military has raised its cybersecurity alert level as tensions rise with neighbor North Korea following Pyongyang’s claim that it successfully tested a hydrogen bomb, Reuters reported.

While many have cast doubt on North Korea’s assertion, South Korea on Thursday restarted its propaganda loudspeaker broadcasts over the border in retaliation for the test. In response, North Korea has increased its number of troops along the border, according to reports.

{mosads}In preparation for a potential assault through cyberspace, South Korea’s military has deployed more cyber defense agents, according to South Korea’s Yonhap News Agency.

North Korea is not considered a top global cyber power, but it has been blamed for a number of high-profile intrusions, including 2014’s destructive hack of Sony Pictures Entertainment.

South Korea has also accused its northern neighbor of orchestrating a series of cyberattacks on South Korean banks and media organizations. More recently, Seoul said Pyongyang was likely behind the hack of a nuclear power plant.

Shortly after this slate of digital assaults, the U.S. and South Korea pledged in May 2015 to strengthen cybersecurity coordination in an effort to counteract North Korea’s cyber efforts.

If confirmed, North Korea’s test this week would be its fourth overall nuclear test, and potentially its first hydrogen bomb test.

But U.S. officials have cast doubt on the claim the exploded device was a hydrogen bomb.

“The initial analysis is not consistent with the North Korean claims of a successful hydrogen bomb test,” White House press secretary Josh Earnest told reporters this week.

Outside experts agree, saying the blast was more consistent with North Korea’s previous nuclear test, in 2013.