South Korean forces fired warning shots and sent out attack helicopters and jets after North Korean drones entered the nation’s airspace on Monday morning.
Five drones entered the South Korean province of Gyeonggi, which surrounds the capital city of Seoul, around 10:25 a.m. on Monday.
One of the drones entered Seoul before returning back to North Korea, according to The Korea Times.
It’s unclear what happened to the other four drones and whether the unmanned aerial vehicles were armed.
South Korea’s Joint Chiefs of Staff said the military operation was ongoing, the Yonhap News Agency reported.
The one drone that entered Seoul could not be shot down because it was flying near a civilian area, a Joint Chiefs of Staff official told the outlet, although attack helicopters and warplanes were launched and warning shots were fired.
North Korea has sent drones near the border with South Korea before, including in both 2014 and 2017.
The latest provocation comes just days after North Korea fired a ballistic missile toward South Korea’s eastern waters.
The Democratic People’s Republic of Korea, the formal name for North Korea, has test-fired an unprecedented number of missiles this year.