North Korea Has Lost ‘Many’ Troops to Mines in DMZ, South Says

A number of North Korean soldiers have been killed or injured by land mines in the Demilitarized Zone that divides the Koreas since late last year, when the North began sending them into the buffer zone to do construction work, the South Korean military said on Tuesday.

The work has been underway since November, when North Korea suspended a 2018 agreement with the South to cease all hostile activity ​around the DMZ, the South’s military said. It said the troops had been sent into the North’s half of the 2.5-mile-wide buffer zone for work that included rebuilding military guard posts that the North demolished under that deal.

The North had ​pressed on with the work despite “many deaths and injuries” caused by several land mine explosions, the South’s military said, without providing further details.​

The South’s military mentioned the casualties as it announced that a group of North Korean soldiers had briefly entered South Korean territory on Tuesday, crossing the military demarcation line that is the official border within the DMZ. It was the second such incident this month; about 20 soldiers did so on June 9, some carrying small arms and others only construction tools, the military said.

On both occasions, the soldiers retreated after the South ​fired warning shots, according to the military, which said it considered the intrusions unintentional. The border line is not always clearly ​visible; there are markers at intervals, but some are missing because of floods or a lack of maintenance, and the line is particularly easy to miss in the summer when vegetation is thick, officials say.

But the episodes added to a sense of tension that has grown between the Koreas​ in recent weeks, with North Korea using balloons to dump