Two seismic events recorded in North Korea were probably not caused by deliberate explosions, according to a nuclear watchdog.
The Comprehensive Nuclear-Test-Ban Treaty Organization, through its executive secretary, tweeted Saturday that the activity was "unlikely man-made".
China's seismic service CENC on Saturday detected a zero-depth, 3.4-magnitude natural disaster in North Korea, calling it a "suspected explosion".
The quake comes amid soaring tensions over Pyongyang's weapons programme, with the firing of two missiles over Japan in recent weeks and its sixth and largest nuclear test earlier this month.
The announcement follows days of increasingly bellicose rhetoric between US President Donald Trump and Kim Jong-Un's regime, which has raised global alarm.
China's official Xinhua News Agency said the country's seismic service detected a magnitude 3.4 quake in North Korea and saw the likely cause as an explosion.
Recently, North Korea conducted its sixth most powerful nuclear test on September 3, attracting United Nations sanctions and criticism from the worldwide community.
"It's worth noting up until the Trump administration's inauguration China was of the view that this was not their problem", Ms Bishop said. The move escalated tensions with the US and North Korea's neighbors, and this week its foreign minister said the regime's options included testing a hydrogen bomb in the Pacific Ocean.
North Korean leader Kim Jong-Un (L) and US President Donald Trump (R). It will also ban imports of textiles from North Korea.
"This event occurred in the area of the previous North Korean nuclear tests", the USGS said. The North Korean dictator said Trump would "pay a heavy price" for his statements.
North Korea's weakest nuclear test, the first one conducted in 2006, generated a magnitude 4.3 quake. Satellite photos of the area after the September 3 quake showed numerous landslides apparently caused by the massive blast, which North Korea said was an advanced hydrogen bomb.
The country also has tested more than a dozen missiles this year, some of which have flown over Japan - a strong US ally.