Seoul, October 20 (QNA) - The South Korean Defense Ministry expressed concerns on Tuesday over North Korea escalating border tensions with threats and criticism of South Korea's military operations conducted in response to a landmine explosion last month that injured South Korean soldiers.

"The Ministry of National Defense expresses grave concern over Kim Yo-jong's criticism of our military's legitimate operations conducted under the Armistice Agreement, as well as her escalation of tensions through military threats," the ministry said in a statement.

"The warning broadcasts and warning shots conducted by our military near the Military Demarcation Line (MDL) are legitimate and defensive measures intended to prevent North Korean troops from violating the MDL and to repel those that cross it," the statement added.

North Korea announced Monday, through Kim Yo-jong, the sister of the North Korean leader, that the situation on the southern border is "very unstable." This followed Pyongyang's repeated denials of responsibility for a landmine explosion last month, which injured three South Korean soldiers, two of them seriously, and its rejection of Seoul's investigation results, which stated that the explosion was caused by landmines intentionally planted by North Korea. (QNA)