North Korea has warned the South Korean navy that it will open fire on its ships if they cross the dividing maritime border, in an emergency alert published by the Korean Central News Agency (KCNA) on Friday.

The warning, issued by the Southwestern Front of the Korean People’s Army (KPA) claimed that South Korean speedboats had crossed onto North Korean territory across the Northern Limit Line (NLL) this week and said further incursions will be met with immediate gunfire.