Shots rang out over the fractious border between North and South Korea early on Sunday (May 3) just a day after North Korean leader Kim Jong Un's reappearance on state media.
Multiple shots were fired from North Korea at 7:41 am local time towards a guard post in South Korea, according to a statement from the latter's Joint Chiefs of Staff.
South Korea responded by firing two shots towards North Korea, and no injuries were reported.
On Saturday (May 2), footage was aired of Kim opening a fertilizer plant - the first report of his appearance since April 11.
During his absence, there has been intense conjecture over his whereabouts and the state of his health including one suggestion that Kim had undergone cardiovascular surgery.
On Sunday, South Korea's Yonhap news agency, citing a senior government official, said that rumor was not true.
But analysts have suggested Kim may be trying to mute speculation that, following his absence, he does not retain full control over the military.
Choi Kang from the Asan Institute for Policy Studies said Kim could be quote: "reminding us, 'yes I'm healthy and I'm still in power'.