An “artificial” earthquake has reportedly been detected in North Korea.

The 2.1-magnitude seismic activity is thought to have been caused by an explosion in a mine, according to the Korea Meteorological Administration.

The earthquake’s epicentre was measured near ground level in the mining town of Pyongyang on Thursday, reported the Korea Times.

Mining is known to cause minor seismic activity but the tremor came shortly after North Korea was reported to be “pursuing the rapid rebuilding” of a missile site it promised to dismantle.

South Korea’s intelligence agency has reportedly been briefed on renewed activity at the Sohae long-range missile launch centre in Tongchang-ri, in North Korea’s northeast.

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The rebuilding was said to have started in the weeks before North Korean leader Kim Jong-un’s failed talks with Donald Trump. Mr Trump said he would be “very, very disappointed” if the reports were true.

New activity has also been detected at a factory that produced North Korea’s first intercontinental ballistic missiles capable of reaching the US, according to South Korea’s JoongAng Ilbo and Donga Ilbo newspapers.

Previous missile and nuclear tests in North Korea have triggered small earthquakes, although there is no evidence to suggest the latest tremors were caused by such tests.

On Thursday, Mr Trump’s national security adviser said the US president was open to further talks with Mr Kim despite reports Pyongyang had reactivated part of its missile programme.