Officials in South Korea say hundreds more trash-filled balloons launched by North Korea have landed in their country.
More than 700 balloons have been found in various parts of South Korea in the last days. The balloons have carried waste paper, cigarette butts and scraps of cloth, but nothing dangerous, the Associated Press reported.
The balloons are reportedly in response to South Korean activists flying anti-Pyongyang propaganda leaflets via their own balloons across the border.
The first wave of balloons started last Tuesday.
"This move by North Korea is a clear violation of international law and seriously threatens the safety of our people," the South Korean Joint Chiefs of Staff said in a statement.
"We issue a stern warning that it must immediately stop its anti-humanitarian and low-level actions."
North Korea has long criticized South Korea for allowing its activists to release balloons into the country carrying items ranging from anti-regime leaflets and electronic devices to medication and bibles.
Along with the balloon launches, the government in Pyongyang has reportedly simulated nuclear attacks on South Korea and jammed GPS navigation systems.
South Korea's national security director said Sunday that top officials plan "unbearable" measures against North Korea in response.
The response could include loudspeaker broadcasts over the border that would include criticism of North Korea's government, world news and K-pop songs.
