North Korea has been reinforcing the border since abandoning a military agreement with South Korea last November.
South Korea’s military has said that between 20 and 30 North Korean soldiers crossed the border between the two countries early on Tuesday, but returned after South Korean forces fired warning shots.
The incident took place at about 8:30am (23:30 GMT on Monday) when a group of North Korean soldiers in the central part of the Demilitarised Zone (DMZ) crossed the military demarcation line, Yonhap news agency reported, citing the Joint Chiefs of Staff (JCS).
The JCS said the group quickly returned after South Korean forces fired warning shots, saying they believed the crossing was not deliberate. A similar incident took place in the central zone of the DMZ just over a week ago.
The South Korean military also said that several North Korean soldiers had been injured or killed in landmine explosions in the border area, but did not say when the incidents took place. The DMZ and line of control across the Korean Peninsula is one of the world’s most heavily fortified and mined borders.
“Many casualties are occurring due to several landmine explosions in the frontline area,” the JCS told reporters.
North Korea said in November that it would abandon a 2018 military agreement with Seoul and move more troops and equipment to the border, after South Korea suspended parts of the deal in response to Pyongyang’s successful launch of its first military spy satellite.
Activity in the area has increased since and the JCS said North Korea was removing streetlights and railway tracks, installing antitank barriers and laying mines to establish “barren land to strengthen security capabilities”.
The latest incident comes as North Korean leader Kim Jong Un prepares to welcome Russian President Vladimir Putin to Pyongyang as the two countries deepen their relationship.
In a letter published in Tuesday’s edition of the Rodong Sinmun, the newspaper of North Korea’s ruling Workers’ Party, Putin said the two countries had developed good relations and partnerships over the past 70 years.
“We will develop alternative mechanisms of trade and mutual settlements that are not controlled by the West, and jointly resist illegitimate unilateral restrictions,” Putin wrote. “And at the same time – we will build an architecture of equal and indivisible security in Eurasia.”
Putin and Kim last met in eastern Russia last September.
