South Korea’s Joint Chiefs of Staff said late Saturday that North Korea was flying balloons loaded with trash once again, as the wind was forecast to veer south.

Following the JCS announcement an alert was issued across Seoul and areas near the border warning residents to beware of falling objects and to report sightings to authorities.

The South Korean military has been watching for another wave of the North Korean balloons after a group of activists called Fighters for Free North Korea tried to send 10 balloons carrying removable drives containing K-pop music and anti-Pyongyang leaflets on Thursday.

The JCS then confirmed that at least a few of those balloons had crossed the border to North.

North Korea sent hundreds of trash-filled balloons into the South last week after failing to launch another spy satellite on May 27, on top of firing short-range ballistic missiles into the sea and other provocations.

Following a warning from South Korea’s National Security Council that it would mull resuming anti-Pyongyang broadcasts along the border as a response on June 2, North Korea said it would not launch more balloons, as long as balloons were not flown in from the South.