North Korea on Tuesday destroyed a liaison office used for diplomatic talks with the South, as tensions escalate in the Korean Peninsula. The office is located in Kaesong, a town located on the North Korean side of the demilitarized zone (DMZ) separating the two countries.

According to North Korean state broadcaster KCNA, the four-story building was completely destroyed by a "terrific explosion" at 2:50 p.m. local time. South Korea’s Defense Ministry warned Pyongyang in a statement that it would “respond with powerful force” if the North continues its provocations.

“We are making a full effort to manage the situation stably so that the situation does not escalate into a military crisis,” the ministry said. “If North Korea carries out military provocation, our military will respond with powerful force."

North Korea destroyed the building after anti-regime leaflets were being repeatedly sent by defectors and activists from South Korea, with these messages landing north of the DMZ.

"The recent foolish act of daring hurt the dignity of our supreme leadership," a statement from the North Korean government said. "The world will clearly see what severe punishment our people will mete out to the South Korean authorities and how they wipe the human scum off the earth."

As a highly secretive country, North Korea views the leaflets as a threat. In 2018, North Korean leader Kim Jong Un and South Korean President Moon Jae-in agreed during a summit to cease "all hostile acts and eliminating their means, including broadcasting through loudspeakers and distribution of leaflets" across the DMZ.

Over the weekend, Kim's sister, Kim Yo Jong, threatened to deploy the North Korean military to the DMZ. The two Koreas are still technically at war, as the Korean War ended in 1953 with a truce, not a peace treaty.

Kim Jong Un has frequently shot off rockets in recent years, threatening the South. In January, Kim promised to unveil a “new strategic weapon,” as North Korea struggles with sanctions amid stalled nuclear talks with the United States. A report released by the Stockholm International Peace Research Institute on Monday also suggests that North Korea could be bolstering its nuclear arsenal. The report estimates that North Korea has added up to 20 nuclear warheads since January 2019, for a total of up to 40 nuclear weapons.