North Korea on Tuesday demolished the inter-Korean liaison office in Kaesong, stepping up its actions against the South.

According to Seoul’s Ministry of Unification, the North demolished the office at 2:49 p.m.

The North had been ratcheting up its rhetoric against the South in a series of statements from top officials including Kim Yo-jong, sister of North Korean leader Kim Jong-un.

The action came hours after the North Korean military warned of plans to refortify disarmed areas along the inter-Korean border, continuing to raise tensions on the peninsula.

In a statement released through North Korean state media, the General Staff Department of the Korean People’s Army revealed that plans were under review concerning the refortification of areas along the border and the resumption of the North’s propaganda campaign.

“We have received opinions on action plans for fortifying the front lines in areas disarmed under the North-South agreement and strengthening military vigilance against the South from the United Front Department and departments concerning relations against the enemy,” the statement said.

Since last week the North has reverted to referring to South Korea as its “enemy,” following orders from top officials including Kim Yo-jong to treat inter-Korean activities as “projects against the enemy.”

Although the statement did not specify the disarmed areas, it has been speculated that areas in and around the Kaesong industrial park and Kumgangsan are likely candidates.

The border city of Kaesong had a heavy military presence until work began on the industrial park in 2003, as the area was considered to have high strategic value for a cross-border invasion. The area around Kumgangsan also had a heavy military presence before the resort was built for cross-border tourism. Reactivation of the Kaesong industrial park and of tourism at Kumgangsan are said to have been high on the North’s list of priorities in talks with Seoul and Washington.

The industrial complex has been closed since 2016 following nuclear weapons tests by the North, and tours to Kumgangsan halted in 2008 after a South Korean tourist was shot dead by a North Korean solider.

The statement from the North’s military also hinted that it would resume its practice of sending propaganda leaflets across the border.

“Opinion for actively cooperating with the large-scale leaflet distribution effort expected from all levels of the people, by opening up many areas along the land front and southwest sea and setting up safety measures, was received,” the statement said, adding that related plans would be submitted to the Central Military Commission of the Workers’ Party of Korea.

“Our military will quickly and thoroughly execute any decisions made by the party and the government.”

South Korea’s Ministry of Unification responded to Tuesday’s development by repeating Seoul’s position that both sides must abide by inter-Korean agreements.

“The South and the North both need to make efforts to adhere to inter-Korean agreements,” a Unification Ministry official said.

On the matter of the North possibly sending propaganda leaflets, the official said doing so would be a violation of the Panmunjom Declaration, but added that the North had yet to take action. The Panmunjom Declaration was issued April 27, 2018, the day of President Moon Jae-in’s first meeting with North Korean leader Kim Jong-un.

Seoul’s Ministry of National Defense took a similarly generic stance, saying only that the military was closely monitoring the North’s armed forces in cooperation with the US, and that the South Korean military was ready to respond to any development.

The news article was previously published in The Korean Herald which is a part of Asia News Network.