The South Korean navy is conducting live-fire exercises all along the country’s coastlines this week to bolster readiness against North Korean naval threats, while commemorating those killed in past DPRK attacks, the military announced on Wednesday.

All three of the country’s fleets are participating in the five-day drills that began on Monday, according to the ROK navy. The exercises involve over 20 naval vessels, including the ROKS Gwanggaeto the Great destroyer and the ROKS Cheonan frigate, as well as 10 aircraft assets.

The navy said the drills are being held to mark West Sea Defense Day in late March, which