

This picture released on April 2, 2014 shows wreckage of a crashed drone found on March 31, 2014 at Baengnyeong island near the disputed waters of the Yellow Sea. (South Korean Defence Ministry/AFP/Getty Images)

If these unmanned aircraft look rudimentary, it's probably because they are: Not only did they all crash, but with only a poor quality camera that could not take video, and no way to broadcast the images, their use as a spy plane is severely limited.

Despite their lack of sophistication, however, the sudden appearance of these drones in South Korea is causing some serious concern.

According to the Chosun Ilbo, one drone crashed on Baeknyeong Island on Monday, not long after the North and South engaged in artillery fire. The others had crashed in Paju, Gyeonggi Province on March 24, the paper reported.

While the South Korean government hasn't formally accused anyone of being behind the drones yet, there's one obvious suspect: North Korea.



This photo provided on Wednesday, April 2, 2014 by the South Korea Defense Ministry, shows an unmanned drone which was found last week in Paju, a South Korean city near the land border with North Korea. (AP Photo/South Korea Defense Ministry)

Why? First, the North is the state with the most reason to attempt to spy on the South. Secondly, Yonhap News has reported that the drones flight route appeared to suggest they began their journey in the North. The drones also bear a strong resemblance to other military drones paraded by the North Korean air force in Pyongyang recently (though those larger drones were much larger and reportedly designed for "suicide" attacks). Finally, a South Korean official has told reporters that the batteries used in the drone had North Korean-style writing on them.



This picture released on April 2, 2014 shows a crashed drone found on March 24, 2014 in Paju, north of Seoul. (South Korean Defence Ministry/AFP/Getty Images)

Experts consulted about the drone seem unanimous in pointing out that it's an extremely unsophisticated affair. "It is like a toy," Kim Hyoung-joong, a cyber-defense professor at Korea University in Seoul, told Reuters, while another expert described it to Yonhap as like a "model airplane."

That doesn't mean it's not worrying. According to Korea JoongAng Daily, one of the drones that crashed on March 24 had managed to take photos of landmarks in central Seoul, including the president's official residence, the Blue House and the Gyeongbok Palace, apparently undetected before it crashed. It's not clear if other drones have done the same.