The boom of artillery fire and rat-a-tat-tat of anti-aircraft guns rang out in the mountains outside Seoul on Thursday, as ROK tanks and U.S. military drones conducted firepower drills simulating an attack on North Korean forces.

The Joint Integrated Firepower Exercises in Pocheon, some 35 miles northeast of the South Korean capital, featured some 300 ROK military personnel and 30 U.S. soldiers and focused on boosting joint interoperability.