SEOUL (REUTERS) - A drone found last week while probably returning to North Korea had flown over the presidential palace in the South before crashing near the border, but would not have been able to carry a bomb, an official said on Thursday.
The drone was the first of two unmanned aircraft found in a span of a week, with the second found soon after a three-hour artillery barrage between the neighbours in waters near a disputed maritime border.
South Korea's military has been criticised for apparently failing to spot or stop the unidentified aircraft that entered its airspace and flew over its capital amid a tense standoff with the North, as both countries remain technically at war.
Nearly 200 aerial photographs were recovered from a camera carried by the drone, including some taken directly above the presidential Blue House, but the aircraft had no equipment to transmit the images, defence ministry spokesman Kim Min-seok said.
"It is of primitive standard, and it would not have been easy to use it in an act of terror, or more precisely, it would not have been possible," he said when asked if it could carry a bomb.
But the North was clearly working to improve the technology, he added. The 1950-53 Korean War between the two countries ended in a truce and no peace treaty has been signed since.
The aircraft was a lightweight model of less than 2 m in length or width, news reports said. It was carrying a camera of a kind widely sold commercially for about 1 million won (S$1,190) and equipped with a basic non-zoom lens, Kim said.
South Korea believes it was launched by the North on the grounds that it flew in from the north and over Seoul before turning back, with enough fuel left when it crashed to carry it back to North Korea.
Images of Monday's drone crash showed the wreckage of a light-blue aircraft with paintwork and markings similar to North Korean drones displayed in a Pyongyang parade last year.
Those drones were larger aircraft modified to crash into pre-determined targets, but are not believed to be capable of air strikes or long-range surveillance flights.
North Korea's state media said last year that leader Kim Jong Un had supervised a drill of "super-precision" drone attacks on a simulated South Korean target.
Although the North has one of the world's largest standing armies, much of its equipment consists of antiquated Soviet-era designs. It has focused resources on developing nuclear and long-range missile programmes.