Seoul says it is “fully ready” for any provocation as Pyongyang deploys eight artillery brigades on the border.

The South Korean military has said it is “fully ready” to respond after reports that North Korean troops have been deployed to the border and are preparing to blow up roads connecting the two nations along the heavily militarized dividing line.

Tensions have escalated in recent days as the nuclear-armed North accused Seoul of flying drones over its capital to drop propaganda leaflets full of “inflammatory rumors and nonsense” and warned that the discovery of another drone would be seen as a “declaration “would be considered war”.

South Korean military spokesman Lee Sung-jun told reporters in Seoul on Monday it was “fully prepared” against the possibility of a “provocation” after Pyongyang ordered artillery units along the border to open fire in the event of an escalation.

South Korea’s state news agency Yonhap also quoted Lee as saying the military had discovered that the North was installing screens along roads “to prepare for the explosions.”

“It is possible that (the explosions in North Korea) could happen as early as today (Monday),” he said. “If North Korea undertakes a provocation, we will retaliate violently in accordance with our right to self-defense.”

Seoul Korea on Monday neither confirmed nor denied that it was responsible for the use of drones across the border, calling the North’s claim “shameless.”

Lee, his military spokesman, instead blamed Pyongyang for inflaming tensions after launching “vulgar and vile garbage balloons” toward the south.

Seoul has previously denied being behind the drone flights, with local speculation focusing on activist groups in the south that have long sent propaganda and the currency of the United States, a close ally of South Korea, north, typically by balloon.

But the North insists Seoul is officially to blame, announcing late Sunday that it had ordered eight artillery brigades already deployed in the war to be “fully prepared to open fire” and strengthened air observation posts in Pyongyang.

Pyongyang claims propaganda drones have invaded the capital’s airspace three times in recent days, and leader Kim Jong Un’s powerful sister threatened a “terrible catastrophe” if they don’t stop.

In a statement early Monday, Kim Yo Jong said the drone flights were “an unforgivable, malicious challenge to our state.”

As part of the North’s retaliation, the country also appeared to be preparing to carry out explosions on roads connecting to the South, Seoul’s military said.

Last week, the North’s military announced the measure would “completely separate” North Korea’s territory from the South.

The two Koreas are technically still at war, after their 1950-53 war ended in an armistice rather than a peace treaty.

The cross-border roads are remnants of times of rapprochement between the countries, including a summit between the leaders in 2018 where they declared that there would be no more war and a new era of peace had begun.

North Korea has reintroduced heavy weapons into the Demilitarized Zone’s border buffer and restored guard posts after both sides declared a 2018 military deal on detente was no longer valid.