Kim Jong Un Didn't Undergo Surgery During Absence from Public Life: News Outlet

North Korean leader Kim Jong Un did not undergo surgery during his almost three week absence from public life, South Korean news outlet Yonhap said citing a senior government official, as the two Koreas exchanged gunfire around the border on Sunday.

The South Korean official declined to provide reasons for believing that Kim did not undergo surgery, but said speculative reports that he may have had surgery, citing some differences in his leg movements, is not true, Yonhap reported.

Earlier on Sunday, North and South Korea exchanged gunfire around the South's guard post, raising tension a day after North Korean state media showed Kim visiting a factory, the first report of him making a public appearance since April 11.

Multiple gunshots were fired from North Korea at 7:41 a.m. local time towards a guard post in South Korea that borders the North, the South's Joint Chiefs of Staffs (JCS) said in a statement.

South Korea responded by firing two shots towards North Korea, no injuries were reported.

After weeks of intense speculation about Kim's health and whereabouts, which included one report he had undergone cardiovascular surgery, North Korea's official media published photographs and a report on Saturday that Kim had attended the completion of a fertiliser plant.

Kim was seen in photographs smiling and talking to aides at the ribbon-cutting ceremony and touring the plant. State TV footage showed Kim’s leg movements appearing stiff and jerky.

The authenticity of the photos, published on the website of the official Rodong Sinmun newspaper, could not be verified.

The exchange of gunshots on Sunday was the latest confrontation between the rival Koreas that technically remain at war.

In a lengthy briefing held later on Sunday, an official at South Korea's JCS said the gunshots did not seem a planned provocation, as the area where it occurred was farmland, but declined to provide a clear conclusion about the incident.

"In absence of vision (for the target) and in the fog, would there be an accurate provocation?" the official said.

'MESSAGE KIM STILL CONTROLS MILITARY'

Choi Kang, vice president of the Asan Institute for Policy Studies, said he believed the timing of the 'grey area' provocation shows it could have been planned to show that Kim was still in charge of the North Korean military.

"Yesterday, Kim was trying to show he is perfectly healthy, and today, Kim is trying to mute all kinds of speculation that he may not have full control over the military,” Choi said.

"Rather than going all the way by firing missiles and supervising a missile launch, Kim could be reminding us, 'yes I’m healthy and I’m still in power'.”

Ewha University international affairs professor Leif-Eric Easley in Seoul said the shooting incident could be aimed at boosting morale in the North Korean military.

"The Kim regime may be looking to raise morale of its frontline troops and to regain any negotiating leverage lost during the rumor-filled weeks of the leader's absence," said Easley.

"South Korea and the United States should not take lightly such North Korean violations of existing military agreements."