It hardly seems coincidental that North Korean leader Kim Jong-un’s first public appearance since April 11 was followed by gunshots fired by the North at a South Korean guard post inside the Demilitarized Zone on Sunday.

Upon finding four bullet marks on the guard post’s wall, the South’s military fired back and issued broadcast warnings in accordance with the response manual.

It marked the first exchange of gunfire between the two Koreas across the border since November 2017, when a North Korean soldier fled to the South at the truce village of Panmunjom.

The incident came one day after the North ended mounting rumors about Kim’s health and whereabouts as its state media reported his attendance at a ceremony marking the completion of a fertilizer plant Friday.

He had not appeared in public for the previous three weeks after he was last seen presiding over a Politburo meeting of the ruling Workers’ Party.

South Korea said North Korea’s latest action violated the bilateral military accord signed in September 2018, which called for a halt to all hostile acts by either side against the other.

The South’s Joint Chiefs of Staff was also quick to downplay the possibility that it was an intentional provocation.

A JCS officer noted that “it was foggy and the North Korean soldiers usually rotate shifts around that time,” referring to the time the shots were fired, and added that no unusual movements by the North’s military had been detected.

But concluding that the firing was an accident appears too hasty, when the North has made no statement on the matter.

The North has yet to respond to a notice from the South sent via the inter-Korean communication line calling for an explanation.

The North’s motivation for firing shots at the South will become clear in the course of time, through the actions it takes down the road.

Kim’s prolonged absence from public view -- particularly his failure to make an annual visit to the mausoleum of his late grandfather, the totalitarian regime’s founder Kim Il-sung -- sparked speculation that he was seriously ill or even dead.

The photos and video clips released by the North’s state media on Saturday showed no apparent signs of Kim having a serious health problem.

As some experts said, he might have been hiding out at a coastal resort to escape the novel coronavirus pandemic. Or he might have actually received some kind of medical treatment without serious risks or complications.

There is also the likelihood that Kim wanted to use his long absence from public view to draw attention from the international community, especially US President Donald Trump.

Until recently, Trump had paid little attention to North Korean issues, as he was preoccupied with the rapid spread of the novel coronavirus in the US and preparing for his reelection bid.

During his press briefings in the past weeks, Trump was asked by reporters to comment on the North Korean leader’s absence from public view.

Trump tweeted Saturday he was glad to see Kim “back and well.”

Trump and Kim have met three times in a bid to dismantle North Korea’s nuclear weapons program in return for economic and diplomatic concessions from the US.

Denuclearization talks between the two sides have ground to a halt since their second summit in Hanoi in February 2019 collapsed due to differences over how to match each other’s steps.

Experts expect Kim to make further provocative acts to put pressure on Trump to be more responsive to Pyongyang’s demands.

His recalcitrant regime may resume missile test-firings and intensify tensions along the inter-Korean border. Sunday’s shooting may portend this course of action.

South Korean President Moon Jae-in’s government seems poised to make an active push for cross-border projects, hoping Kim’s reappearance will give impetus to such efforts.

But its eagerness to promote inter-Korean economic cooperation is unlikely to be met with a positive response from Pyongyang and may risk weakening the joint stance with Washington in handling the North Korean nuclear issue. The US State Department last month made clear Washington’s wish that inter-Korean projects would proceed in step with progress in the North’s denuclearization.

What South Korea needs to do now is to tighten its security posture in preparation for the North’s possible attempt to ramp up tensions on the peninsula to strengthen its bargaining power.

In this regard, it is worrisome that the South Korean military has recently been plagued by a series of lax discipline cases and raised no objection to cutting the defense budget to help fund a supplementary budget designed to provide coronavirus relief money to all households.