NORTH KOREA (WCMH/AP) — Several news outlets are reporting that a tunnel has collapsed at a North Korean nuclear test site, killing 200 people.

According to Yahoo UK citing Japan’s TV Asahi, another 100 people are trapped inside the collapsed area.

Any future nuclear test by North Korea risks collapsing its mountain test site and triggering a radiation leak, South Korea’s weather agency chief said Monday.

The head of the Korea Meteorological Administration, Nam Jae-Cheol, made the comments during a parliament committee meeting in response to a lawmaker’s question about whether another North Korean test could lead to such an accident.

Analysts believe North Korea will likely conduct more nuclear and missile tests to try to build a reliable arsenal of nuclear-tipped missiles capable of striking anywhere in the mainland U.S. It’s unclear when and where those tests could take place.

North Korea’s foreign minister said last month that his country could conduct a hydrogen bomb test over the Pacific Ocean.