This photo shows unmanned drones found in Paju, Gyeonggi Province, on March 24.

Seoul officials said Wednesday that North Korea was “highly likely” to have deployed the two crashed drones recently discovered in South Korea’s frontline regions. 

After the drones were found on the border island of Baengnyeongdo on Monday and in Paju, Gyeonggi Province, a week earlier, speculation rose that the communist state might have deployed them for espionage activities.

Amid growing criticism of a “porous” air defense, Seoul is considering quickly introducing radars capable of detecting objects flying at low altitudes, and bolstering its air defense mechanism.

“We judged that the drone traveled from the North to Seoul and crashed on its way back to the North. We found that there was enough fuel left for it to return home,” a senior government official told reporters.

“The drone also carried a military parachute for its landing. All this shows that the drone is highly likely to have come from the North.”

Military investigators also found North Korean spelling for the dates for the period of usage for the lithium-ion battery of the drone, the official said.

The official added that the drones appeared to be “entry-level surveillance aircraft.” But he noted that with more technological advancements, the North could develop them into more powerful military aircraft.

After finding the suspicious drones, military authorities and intelligence officials launched a joint investigation to ascertain their origin and analyze intentions behind the deployment of such military assets.

Top officials from the presidential office of national security, the Defense Ministry, Joint Chiefs of Staff and Capital Defense Command planned to discuss ways to counter threats from North Korean drones this week, officials said.

The sky-blue drone found in Paju was V-shaped and carried a camera with a 24 mm optical lens made in Japan. It filmed Paju and other areas in northern Gyeonggi Province and parts of Seoul.

The drone was programmed to return home after completing missions in preset locations. It did not have any wheels, but carried a military parachute for its landing.

The drone found on Baengnyeongdo Island also carried a Japanese camera. It reportedly took photos of major marine facilities on the northwestern islands near the tense inter-Korean sea border.

Experts presumed that the drones appeared to have been built based on the “Banghyon” drones. Seoul officials believe that Pyongyang imported Chinese-made D-4 drones, modified them to make Banghyon drones and deployed them to frontline units.

With an operational range of 4 kilometers, the 3.23-meter-long Banghyon drone flies at an altitude of 3 kilometers and a top speed of 162 kilometers per hour. It can also carry 20-25 kilograms of explosive devices.

To counter threats from North Korea’s drone campaigns, Seoul is reportedly seeking to introduce more advanced radar and develop a jamming system to disrupt drone operations and a system to intercept unmanned aircraft.

By Song Sang-ho (sshluck@heraldcorp.com)