North Korea blew up roads on border with South Korea. South Korean military fired warning shots in response. Explosions did not cause damage to the South Korean side of the border, Joint Chiefs of Staff of South Korean Armed Forces said.
"North Korea blew up sections of the Gyeonggi and Donghae roads north of the Military Demarcation Line around noon," the Joint Chiefs of Staff of the South Korean Armed Forces said in a statement.
The military said it had stepped up surveillance and preparedness to respond.
Last week, the General Staff of the Korean People's Army warned that it would close all roads and railways connected to South Korea from October 9.
"The acute military situation on the Korean Peninsula requires our army to take more decisive and powerful measures to further reliably protect national security," the North Korean General Staff said in a statement released by KCNA.
"For our army, the permanent closure and blockade of the southern border with the Republic of Korea, the main hostile state and the unchangeable enemy, is a measure of self-defence in the current situation to prevent war and protect the security of the DPRK," Pyongyang stressed.