North Korea has blown up sections of inter-Korean roads and rail lines on its side of the heavily fortified border between the two Koreas, South Korea's military said on Tuesday, ratcheting up tensions on the Korean peninsula.

At around midday, some northern parts of the roads and rail lines connected to the South were blown up, the Joint Chiefs of Staff (JCS) said in a message sent to media.

In response, South Korea's military fired warning shots south of the military demarcation line dividing the neighbors, though the explosions had not caused any damage on Seoul's side of the border, it said.