North Korea accused South Korea of flying drones into its airspace, claiming it downed two drones using electronic warfare and warning of consequences for what it called provocative acts.

South Korea denied the allegations, saying it did not operate drones on the dates cited and ordered an investigation.

The incident is expected to further strain relations and complicate South Korea’s liberal government’s efforts to revive dialogue with the North.

North Korea has rejected recent reconciliation overtures and remains focused on strengthening its nuclear program after talks with the United States collapsed in 2019, ABC News has reported.

Drone flights have repeatedly fueled tensions between the two Koreas, with both sides accusing each other of airspace violations in recent years.