North Korea blew up sections of the deeply symbolic roads and railways connecting it to the South on Tuesday, Seoul鈥檚 military said, adding it had conducted a 鈥榗ounter-fire鈥� operation in response.
Pyongyang鈥檚 military last week vowed to permanently seal its southern border after spending months laying mines and building anti-tank barriers in the wake of leader Kim Jong Un declaring the South his country鈥檚 鈥榩rincipal enemy鈥�.
The North also accused Seoul of using drones to drop anti-regime propaganda leaflets on the capital Pyongyang, with Kim convening a security meeting to direct a plan of 鈥榠mmediate military action鈥� in response, state media reported Tuesday.
鈥楴orth Korea has detonated parts of the Gyeongui and Donghae roads north of the Military Demarcation Line,鈥� the Joint Chiefs of Staff said Tuesday, referring to inter-Korean infrastructure that once connected the two countries.
鈥楾here has been no damage to our military, and our forces conducted counter-fire in areas south of the MDL,鈥� it added.
The JCS added late Tuesday that some sections of railways connecting the North to the South had also been detonated, without giving further details.
The infrastructure have long been shuttered, but destroying them sends a clear message that Kim is not prepared to negotiate with the South, experts said.
鈥楾his is a practical military measure related to the hostile dual-state system that North Korea has frequently mentioned,鈥� Yang Moo-jin, president of the University of North Korean Studies in Seoul, told AFP.
The North may also be looking to erect more physical barriers along the border, Yang said, adding that the road detonations could be 鈥榩reparatory work.鈥�
South Korea鈥檚 military released video footage showing North Korean soldiers in military uniforms ahead of a huge explosion, which emitted thick billowing smoke as it blew up sections of the Gyeongui road.
More footage, apparently from after the blasts, showed excavators digging, while soldiers worked as large red trucks arrived.
The Seoul military also released separate footage showing North Korea blowing up a section of the Donghae road, on the east coast.
South Korea鈥檚 unification ministry slammed the North for what it called an 鈥榚xtremely abnormal鈥� provocation, adding that Seoul had shouldered millions in costs for building the infrastructure.
鈥楴orth Korea still has repayment obligations regarding this funding,鈥� it added.
China, a traditional ally of the North, called on all parties 鈥榯o avoid further escalation of conflicts鈥� on the peninsula, a foreign ministry spokeswoman said.
Seoul鈥檚 military initially denied sending drones north but has subsequently declined to comment, even as Pyongyang has blamed them directly, warning it would consider it 鈥榓 declaration of war鈥� if another drone was detected.
Later Tuesday, the powerful sister of North Korean leader Kim Jong Un released a statement, saying Pyongyang has secured 鈥榗lear evidence鈥� that the South Korean military was behind the drones that reached Pyongyang.
鈥楾he provocateurs will have to pay a dear price,鈥� Kim Yo Jong said.
Activist groups in the South have long sent propaganda northwards, typically carried by balloons, but enthusiasts are also known to have flown small, hard-to-detect drones into the North.
Unlike conventional drones made of metal, the devices they used were constructed from expanded polypropylene, similar to Styrofoam, allowing them to go undetected by both South and North Korean authorities, according to enthusiasts who spoke to local media.
At Kim鈥檚 meeting Monday, officials heard a report on the 鈥榚nemy鈥檚 serious provocation鈥�, said KCNA, adding Kim had 鈥榚xpressed a tough political and military stand鈥�.
The North has said the United States, which has a military alliance with South Korea, should also be held responsible.
North Korea has itself sent drones southwards 鈥� in 2022, five of Pyongyang鈥檚 drones crossed the border, prompting the South Korean military to fire warning shots and deploy fighter jets.
The jets failed to shoot down any of the drones.
In July, Seoul said it would deploy drone-melting lasers this year, adding the South鈥檚 ability to respond to provocations would be 鈥榮ignificantly enhanced鈥�.
Now, it is a question of whether 鈥楴orth Korea will respond by sending drones into the South or take strong action if drones infiltrate its territory again鈥�, said Cheong Seong-chang of the Sejong Institute.