This is the coastal area of Gaepung County in North Korea's Hwanghae Province, as seen from the Aegibong Observatory in Gimpo, Gyeonggi Province.

It is an area separated by the Han River and only about 1.5 kilometers away from North Korea.

Two North Korean soldiers are sitting atop a self-propelled artillery piece inscribed in white lettering with the slogan: "Annihilate the U.S. imperialist aggressors, the sworn enemy of the Korean people!"

Using the self-propelled artillery as a seat, they are seen stretching out their legs and chatting, while the gun barrel is also observed moving slowly from side to side and up and down.

The weapon is presumed to be the North Korean military's "122mm self-propelled gun," which has a maximum range of 24 kilometers and is a core artillery asset deployed in large numbers along the front line.

About three North Korean self-propelled guns positioned near the riverbank are clearly visible.

While troops have often been spotted building tactical roads or barbed-wire fences, analysts note that exposing self-propelled artillery in this way is unusual.

Sending artillery weapons—which typically must avoid location exposure—down in virtually defenseless fashion so that they can be filmed by South Korean cameras is seen as a "show-of-force" demonstration aimed at escalating tensions.

[Yang Uk / Research Fellow, The Asan Institute for Policy Studies: "Rather than 'reinforcing firepower,' they are 'making firepower visible.' If actual combat were imminent, the urge to conceal it would be stronger; they would not seek to expose it like that."]

With North Korea having declared that it would resume anti-South loudspeaker broadcasts within this month, residents in border areas are growing restless as self-propelled artillery has also appeared.

[Kim Yu-seong / Resident of Ganghwa County, Incheon: "When that roaring noise rings out, it sounds just like ghosts wailing. In winter, if you shut the doors, it is somewhat bearable, but in the summer, nobody can sleep with the doors closed."]

The fact that booming noises from the North Korean military detected along the front near Ganghwa County, Incheon, have reached some 900 times so far this year is also heightening anxiety.

[Resident of Ganghwa County, Incheon: "It sounds extraordinarily loud, like cannon fire. It startles you. We even half-joke, 'Aren't they invading?'"]

Residents of the Paju border area held a press conference opposing mutual slander through loudspeakers and military confrontation.

(Reported by Kim Min-jun | Written by Yoon Seong-sik | Video by Yang Ji-hun | Video Editing by Choi Jin-hwa | Graphics by Kang Yoon-jeong)