South Korea Holds Military Drills

South Korea conducted military drills Monday without incident using live ammunition near its border with North Korea, according to media reports.

North Korea on Sunday, ahead of the drills, said it would retaliate in a “merciless counterstrike,” if any activity was detected within its waters, reported the Korea Herald, citing Pyongyang’s Korean Central News Agency.

South Korean soldiers fired off a number of different types of weapons in the waters of the five northwestern islands belonging to the country. The drills included self-propelled guns, mortars, anti-aircraft weapons, and attack helicopters, according to the Herald. Meanwhile, the U.S. and Korea have begun joint anti-submarine drills in the area.

“North Korea is thought to have maintained heightened readiness posture (during the exercise), but details are not confirmed,” a spokesperson with the U.S. Joint Chiefs of Staff told the Herald. 

The spokesperson added that the U.S. and South Korea “will continue to hold firing drills for improving readiness posture in the West Sea islands. If the enemy provocation occurs in response to routine exercises we plan to take accurate and swift punitive measures.”

One of the islands where the drills were held is Yeonpyeong, which was shelled by North Korea in late 2010—the first attack carried out by the isolated communist country since the Korean War six decades earlier.

“We notified people living on the five islands they should evacuate into safe zones ahead of the firing drills,” an official with the Joint Chiefs of Staff told the Yonhap news agency.