South Korea's spy agency said on Thursday that it cannot rule out the possibility that one of the North Korean drones that recently infiltrated South Korean airspace filmed the presidential office in Seoul.

According to Rep. Youn Kun-young of the main opposition Democratic Party, the National Intelligence Service(NIS) confirmed that one of the North Korean drones passed through the northern part of the “P-73” no-fly zone that encompasses the presidential office.

Youn said he expressed concerns about the possibility of the drone filming the presidential office during a closed-door briefing to the parliamentary intelligence committee, to which the NIS said "there was a possibility."

Regarding the NIS response, Rep. Yoo Sang-bum of the ruling People Power Party said that the NIS simply meant it "could not rule out the possibility" in response to a hypothetical question, not that it was possible.

According to Yoo, the NIS also said that the North possesses around 500 unmanned aerial vehicles of 20 different types that are mostly small-sized. The NIS said the North is also presumed to have a small number of self-destruct attack drones.