SEOUL, South Korea (AP) — North Korea on Tuesday blew up some of its front-line guard posts as part of an agreement to ease tensions along its heavily fortified border with South Korea, Seoul's Defense Ministry said.

In September, the Koreas' militaries agreed at a leaders' summit in Pyongyang to eventually dismantle all guard posts inside the 248-kilometer (155-mile) -long, 4-kilometer (2.5-mile) -wide border. They later withdrew weapons and troops from 11 of their guard posts and decided to completely dismantle 10 of them by the end of November.

Seoul's Defense Ministry said it confirmed the dismantling of 10 North Korean guard posts on Tuesday. A ministry statement said North Korea had informed the South of its plans in advance.

South Korea began dismantling 10 of its guard posts with dynamite and excavators last week. Ministry officials said Tuesday that they haven't completed the demolitions yet.

The Korean border, the world's most heavily armed with an estimated 2 million land mines, has been the site of deadly fighting and bloodshed. Called the Demilitarized Zone, it was originally created as a buffer at the end of the 1950-53 Korean War.

South Korea had about 60 posts inside the DMZ guarded by layers of barbed wire and manned by troops with machine guns. North Korea was estimated to have 160 such front-line posts. Once the dismantling is done, the two Koreas are to jointly verify their work by the end of December. They haven't decided when they will dismantle the rest of the guard posts.

Under the September agreements, the Koreas have also taken steps to disarm their shared border village of Panmunjom, halted live-fire drills along the border and have been removing mines at a front-line area to conduct their first joint searches for Korean War dead.

Relations between the Koreas have improved since North Korean leader Kim Jong Un reached out to South Korea and the United States early this year with a vague promise to achieve the denuclearization of the Korean Peninsula. U.S.-North Korea talks on the North's nuclear program haven't produced much progress since Kim and U.S. President Donald Trump held the countries' first summit in Singapore in June.