North Korea appears to have blown up tunnels at its only nuclear test site, in a move to reduce regional tensions.
Foreign journalists at the Punggye-ri nuclear testing site said they witnessed a huge explosion.
The North offered to scrap the site earlier this year as part of a diplomatic rapprochement with South Korea and the US, reports BBC.
But scientists believe it partially collapsed after the last test in September 2017, rendering it unusable.
Independent inspectors were not allowed to attend the dismantling of the Punggye-ri site in the mountainous north-east of the country.
The tunnels were collapsed in a series of explosions in front of about 20 handpicked international journalists. Two blasts were reportedly carried out in the morning, and four in the afternoon.
Sky News' Tom Cheshire was among the journalists present. He said the doors to the the tunnels were "theatrically rigged" with "wires everywhere".
"We hiked up into the mountains and watched the detonation from about 500m away," he was quoted by Sky News as saying.
"They counted it down - three, two, one. There was a huge explosion, you could feel it. Dust came at you, the heat came at you. It was extremely loud."
