The South Korean military said North Korea fired about 80 artillery shells into waters north of the de facto maritime border between the two countries on Thursday night.

South Korea's Joint Chiefs of Staff said North Korea's action took place at around 11:28 p.m., some two hours after Pyongyang launched three short-range ballistic missiles from an inland location.

They said North Korea fired the shells eastward from a site in or near the county of Kumgang in the southeastern province of Kangwon.

They also said that the shells hit the military buffer zone north of the Northern Limit Line. The maritime demarcation boundary was set between the two Koreas by the United Nations Command after the armistice agreement over the Korean War in 1953.

The South Korean military sternly warned North Korea to immediately halt its provocations. It said the spate of provocative actions by North Korea undermines the peace and stability of the Korean Peninsula as well as the wider international community.