SEOUL, South Korea (AP) — North Korean leader Kim Jong Un supervised salvo launches of the country’s “super-large” multiple rocket launchers that simulated a nuclear counterattack against enemy targets, state media said Tuesday, adding to his belligerent testing activities and threats that have raised tensions in the region.

The report by North Korea’s official Korean Central News Agency came a day after the South Korean and Japanese militaries detected the North firing what they suspected were multiple short-range ballistic missiles from a region near its capital, Pyongyang, toward its eastern seas.

Analysts say North Korea’s large-sized artillery rockets blur the boundary between artillery systems and ballistic missiles because they can create their own thrust and are guided during delivery. The North has described some of these systems, including the 600mm multiple rocket launchers that were tested Monday, as capable of delivering tactical nuclear warheads.