The South Korean Navy has begun new three-day anti-submarine exercises in the Sea of Japan near the heavily armed border a month after deadly North Korean artillery attacks.

The country had planned to conduct only 47 drills this year, but will conduct one more due to the continuing tension with North Korea.

Six naval ships and anti-submarine helicopters will be participating in the drills, aimed at demonstrating the South Korean military’s readiness for any surprise attacks.

The South Korean Army and Air Force will also hold joint firing drills involving 800 troops, F-15K and KF-16 jet fighters, K-1 tanks, AH-1S attack helicopters and K-9 self-propelled guns.