While we were winding down last night after a long day covering CES 2016 and the rest of the country was finishing up its day as well, North Korea was detonating a nuclear bomb.

At 10:00 a.m. local time in the Eastern country, a Kim Jong Un ordered test of what the country claims to have been a small hydrogen bomb set off seismic activity alarms in South Korea and Japan, registering as a 5.1 magnitude earthquake. The alarms led both nations to believe immediately that a nuclear device had been tested in North Korea and their concerns were confirmed when North Korean state TV announced the test later in the morning.

North Korea last tested a nuclear bomb in 2013, and this is the fourth time North Korea has detonated a nuclear device in recent years.

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“Let the world look up to the strong, self-reliant nuclear-armed state,” Kim Jong Un said in a hand-written note that was displayed on state TV following the test. According to North Korea’s claims, the device in question was a small hydrogen bomb. Experts in South Korea have cast doubt on the claim that it was actually an H-bomb, however.

South Korean officials say that the bomb’s yield was approximately 6 kilotons, which Reuters reports is roughly the same size as the atomic bomb detonated in North Korea’s previous test. “Given the scale, it is hard to believe this is a real hydrogen bomb,” Korea Defense and Security Forum fellow Yang Uk said. “They could have tested some middle stage kind (of device) between an A-bomb and H-bomb, but unless they come up with any clear evidence, it is difficult to trust their claim.”

Other experts seem to agree that the device in question is likely a hybrid bomb rather than a true hydrogen bomb.

“Because it is, in fact, hydrogen, they could claim it is a hydrogen bomb,” security expert Joe Cirincione of the Ploughshares Fund said. “But it is not a true fusion bomb capable of the massive multi-megaton yields these bombs produce.”

North Korea said this most recent nuclear test was an “act of self-defense” to ensure it is protected against threats from its enemies, including the United States.

Zach Epstein has worked in and around ICT for more than 15 years, first in marketing and business development with two private telcos, then as a writer and editor covering business news, consumer electronics and telecommunications. Zach’s work has been quoted by countless top news publications in the US and around the world. He was also recently named one of the world's top-10 “power mobile influencers” by Forbes, as well as one of Inc. Magazine's top-30 Internet of Things experts.