(ATTN: ADDS unification ministry's response, details of video footage in paras 6, 12)
By Koh Byung-joon and Oh Seok-min
SEOUL, June 16 (Yonhap) -- North Korea blew up the inter-Korean joint liaison office in its border town of Kaesong on Tuesday, sharply escalating tensions on the Korean Peninsula after near-daily threats to punish Seoul over anti-Pyongyang propaganda leaflets.
The surprise explosion sparked concern that the communist nation could put other threats against the South into action, including taking military action and moving troops to border regions disarmed under inter-Korean agreements.
South Korea expressed "strong regret" and warned the North not to aggravate the situation.
"The destruction ... is an act that breaches the hope of all people wishing for the development of inter-Korean relations and a lasting peace on the Korean Peninsula," Cheong Wa Dae said in a statement after an emergency meeting of the National Security Council.
"The government makes clear that all responsibility caused by this rests totally with the North Korean side," he said. "We sternly warn that if North Korea takes steps further aggravating the situation, we will respond strongly to it."
The unification ministry also issued a statement, calling the destruction "senseless' and "unheard-of" in inter-Korean relations and a violation of a 2018 summit agreement between the two Koreas, saying that Pyongyang should take full responsibility for the act.
Earlier, North Korea's state media confirmed that the liaison office was "completely ruined."
"The relevant field of the DPRK put into practice the measure of completely destroying the North-South joint liaison office in the Kaesong Industrial Zone in the wake of cutting off all the communication liaison lines between the north and the south," the North's Korean Central News Agency (KCNA) said.
The destruction was in line with "the mindset of the enraged people to surely force human scum and those, who have sheltered the scum, to pay dearly for their crimes," KCNA said, referring to North Korean defectors in the South sending anti-Pyongyang propaganda leaflets.
"At 14:50, the liaison office was tragically ruined with a terrific explosion," it said.
Earlier, witnesses and sources said smoke was seen and an explosion was heard from the border town, with residents in South Korea's northernmost village of Daeseong-dong saying that dark smoke began billowing with a bang sound.
CCTV footage from a camera set up at the border control office showed white smoke rising from the ground along with a quick flashing explosion and window frames of a nearby building falling down from the shock.
The explosion came days after Kim Yo-jong, sister of North Korean leader Kim Jong-un, warned Saturday night that, "Before long, a tragic scene of the useless North-South joint liaison office completely collapsed would be seen."
The North has been lashing out at the South almost daily for failing to stop defectors from sending anti-Pyongyang leaflets across the border via balloons. Pyongyang has vowed to deal with South Korea as an "enemy," cutting off all cross-border communication lines, and threatened to take other measures, including military action.
Following the explosion in Kaesong, the South Korean military tightened its surveillance and readiness posture for possible accidental clashes near the tense border areas, according to officials.
Earlier in the day, the General Staff of the (North) Korean People's Army warned that it is reviewing an action plan to advance into "the zones that had been demilitarized under the north-south agreement, turn the front line into a fortress and further heighten the vigilance" against the South.
"As of now, no unusual, specific military moves by the North Korean military have been detected. We are closely monitoring them," an officer of the Joint Chiefs of Staff said.
The demolition of the liaison office marked the latest setback in inter-Korean relations, which have been almost stalled since a no-deal summit between Pyongyang and Washington in February last year.
Last October, North Korea demanded the South tear down all "unpleasant-looking" facilities at the now-shuttered Mount Kumgang resort on its east coast. Launched in 1998, the tour program was a symbol of inter-Korean reconciliation and cooperation.
China's foreign ministry said Beijing hopes that peace and stability will be maintained on the Korean Peninsula despite the latest development.
The two Koreas launched the liaison office in September 2018 to facilitate inter-Korean exchange and cooperation amid a reconciliatory mood created by summit talks between their leaders.
The office suspended its operations in early January due to concerns over the coronavirus pandemic.