The South Korean military has adopted an aggressive counter-drone operational principle, under which a single North Korean drone infiltration would prompt it to send 10 or more unmanned aerial vehicles into Pyongyang, a source said Tuesday.

The measure is part of Seoul's efforts to beef up air defenses after five North Korean drones intruded across the inter-Korean border in December last year, with one of them having penetrated a no-fly zone close to Seoul's presidential office.

The Cabinet approved a plan Tuesday to establish a drone operations command in September, in a culmination of counter-drone efforts.

"The military's internal determination is to send 10 or more drones to Pyongyang and have them fly over key targets there if North Korea sends one drone over the skies of Seoul," the source said on condition of anonymity.

The military plans to secure 100 small drones, which can cover the whole of North Korea for reconnaissance operations, by the end of this month. It is also known to have procured drones suited for long-duration reconnaissance operations.

The small drone is said to be equipped with cutting-edge systems, including a GPS device, an inertial guidance system and a program designed to burn data storage if it crashes in North Korea.

The envisioned drone command is tasked with a wide range of missions, including surveillance, reconnaissance and strike operations, and psychological and electromagnetic warfare, as well as the operational development of drone assets, according to the plan.

The North's drone incursions in December sounded an alarm for policymakers, as unmanned vehicles could carry lethal weapons targeting key facilities in the South.

To address those concerns, South Korea has pushed for a series of measures, such as holding regular air defense drills and securing drone jamming guns and other assets. (Yonhap)