At least 200 people have been killed at Kim Jong-un's nuclear test site in North Korea after a tunnel collapsed.

A news agency quoted a North Korean official as saying that a collapse occurred during the construction of an underground tunnel at the Punggye-ri nuclear test site in the northeast of North Korea on October 10.

According to the report, 100 people were trapped in underground tunnels, and a further collapse occurred during the rescue operation, suggesting that a total of 200 people may have been killed.

The accident is due to the weakening of the surrounding grounds due to the sixth nuclear test that was conducted here on September 3, TV Asahi reported.