North Korea has sent a letter to the U.N. Security Council (UNSC) president accusing Seoul of staging a recent land mine blast that injured ROK troops in the Demilitarized Zone (DMZ), after South Korea sent its own letter blaming Pyongyang for the explosion and heightened border tensions.

In a statement released Monday, the state-run Korean Central News Agency (KCNA) said North Korea’s U.N. representative addressed the incident in the letter to UNSC President Aglaia Balta.

South Korea conducted a “sinister obstructive move” to portray the North’s efforts to fortify its side of the border as a “military incursion” and obstruct