Seoul has responded with "counterfire" and strengthened its preparedness, according to the military.
Just hours before the explosions, state media in North Korea reported that dictator Kim Jong-Un had met with the highest representatives of the military and security apparatus.
There, Kim is said to have described the drone flights that South Korea is accused of as "the enemy's serious provocation" and presented a plan for "immediate military action" to protect the closed dictatorship.
Destroying the border roads, which were not in use, is in line with Kim's plans to completely sever contact with South Korea. It is a way for North Korea to cement the image of its southern neighbor as the main enemy.
