A North Korean MiG-19 fighter jet crashed during a training exercise Tuesday, according to South Korean military officials.

The crash occurred near Taetan Air Base in South Hwanghae Province during a training exercise of the Korean People’s Army Air and Anti-Air Force.

All aircraft in North Korean airspace have reportedly been grounded since the accident occurred. Pyongyang is likely investigating the cause of the crash and taking other precautionary measures as well as inspecting the maintenance and condition of the rest of their aircraft.

South Korean authorities said that since it’s been more than 40 years since the introduction of