South Korea's spy agency said recently the North was readying possibly two more tunnels following its latest test, according to ruling Democratic Party lawmakers who had been briefed on the issue.
The quake took place at 16.41 UTC (5.41am NZT) at a depth of 5km, the US Geological Survey reported. But South Korea's Meteorological Administration says the quake was natural.
The epicenter of the seismic event is located approximately 25 km away from Sungjibaegam, a town close to the Punggye-ri nuclear test site, at the depth of five kilometers. "The event has quake like characteristics, however, we can not conclusively confirm at this time the nature (natural or human-made) of the event", the USGS said in a statement.
It was the latest in a string of aftershocks following North Korea's sixth nuclear test on September 3, which caused a 6.3 magnitude quake, according to the USGS. The tremor was the latest in a string of at least three shocks to be observed since Pyongyang's September 3 nuclear test, which caused a 6.3 magnitude quake.
And now the latest natural disaster to hit the region suggesting the detonations have dramatically destabilised the area.
When compared to the tremors registered during any of North Korea's previous nuclear tests, the authorities said that the strength of Friday's quake was much lower. Foreign Minister Ri Yong Ho said last month the North could test "an unprecedented scale hydrogen bomb" over the Pacific Ocean, in response to U.S. President Donald Trump's threat to "totally destroy" the country.
Previous tests had caused stronger quakes, with all of them stronger than 4.3 magnitude.
Tensions between North Korea and western powers have escalated in recent months, with North Korean leader Kim Jong Un threatening the United States, in particular, with war.