SEOUL (Reuters) - South Korea has found what appears to be a North Korean drone equipped with a camera on a mountain near its border with the isolated nation, the South’s military said on Friday, suggesting the device was on a spying mission.

A small aircraft what South Korea's Military said is believed to be a North Korean drone, is seen at a mountain near the demilitarised zone separating the two Koreas in Inje, South Korea in this handout picture provided by the Defence Ministry and released by News1 on June 9, 2017. The Defence Ministry/News1 via REUTERS

Its appearance a day after Pyongyang tested a new type of anti-ship missile on Thursday, could spark questions about the state of South Korea’s air defences at a time when Seoul is trying to rein in the North’s nuclear and missile programmes.

In size and shape, the device looked like a North Korean drone found in 2014 on an island near the border, South Korea’s Office of Joint Chiefs of Staff said in a statement, adding that authorities plan to conduct a close analysis.

“The drone found this time looks sloppy but slightly more slender than previous ones,” a South Korean military official told Reuters on condition of anonymity, because he was not authorized to speak to the media.

The device would be the latest of several North Korean drones to have flown into the South, with which Pyongyang is technically at war after the Korean war ended in a truce, rather than a peace treaty, in 1953.

In 2014, South Korea said three unmanned drones from North Korea were found in border towns.

A joint investigation by South Korean and U.S. militaries has concluded the craft were on reconnaissance missions for the North, which has denied sending spy drones, however, dismissing the findings as a fabrication.

Last year, South Korea fired warning shots at a suspected North Korean drone, forcing it to turn back.

North Korea owns around 300 unmanned aerial vehicles of different types including reconnaissance, target and combat drones, the United Nations said in a report last year.

The North Korean drones recovered in South Korea were probably procured through front companies in China, with parts manufactured in China, the Czech Republic, Japan and the United States, it added.