SEOUL, South Korea (AP) — In a symbolic display of anger, North Korea on Tuesday blew up the northern section of unused roads that once linked it with the South, with the rivals exchanging threats days after the North claimed that its rival flew drones over its capital Pyongyang.

North Korea blew up a section of inter-Korean roads and rail route on its side of the border between the two Koreas, prompting South Korea's military to fire warning shots. NBC News' Janis Mackey Frayer reports on the rising tension between the two countries.