South Korea has confirmed firing warning shots after North Korean soldiers briefly crossed the military demarcation line in the Demilitarised Zone before retreating. Pyongyang condemned the move as a “deliberate provocation,” warning of “uncontrollable” tensions, according to BBC.

The incident occurred as President Lee Jae Myung departed for visits to Tokyo and Washington, and amid North Korea’s efforts to seal its border. Despite Seoul’s suspension of propaganda broadcasts to ease hostilities, relations remain strained. The two Koreas, divided since the 1953 armistice, are still technically at war.