The northern and western side of the Punggye-ri nuclear test site in North Korea's mountainous North Hamkyong Province, are seen in this satellite image taken by Airbus Defence & Space, Sept. 17, 2020, and released by 38 North Sept. 24 that year. Yonhap
North Korea seems to be working on a "shortcut" to a tunnel at its nuclear test site in Punggye-ri, apparently aimed at making speedy preparations for a seventh underground nuclear detonation, according to government sources in South Korea, Sunday.
If carried out, it would be the secretive nation's first known nuclear test in four-and-a-half years.
South Korea's military and intelligence authorities have detected signs of the country focusing on restoring Tunnel 3 in the mountainous northeastern area, they said.
"(The North) abruptly stopped its initial construction work to restore the entrance to Tunnel 3, and it is digging up the side (of the tunnel)," a source said, requesting anonymity. "In this way, it seems like it will be possible to restore (the facilities) in a month."