South Korean military says 350 waste balloons detected from North Korea overnight as tensions flare

South Korea spotted another 350 North Korean balloons “presumed” to be carrying waste on Monday, reigniting a tit-for-tat exchange as tensions on the Korean Peninsula continue to heighten.

South Korea’s Joint Chiefs of Staff said a suspected balloon was seen flying in northern Gyeonggi Province, which borders Seoul, around 9 p.m. local time (8 p.m. ET).

About 100 of the balloons fell inside South Korean regions, most of which were found in north of Gyeonggi Province and capital Seoul with “no hazardous substances” found so far, it said.

Seoul’s Metropolitan government later sent out a push notification alerting the city that a North Korean balloon had entered the sky over Seoul, adding that citizens should refrain from touching downed balloons and report any sightings to authorities.

The South Korean military has warned it could restart loudspeaker propaganda broadcasts at the border — which it had paused for the last few years — adding whether Seoul resumes the loudspeakers is “up to North Korea’s actions.”

“Our military is ready to immediately start anti-North Korea propaganda broadcasts, and will operate with flexibility according to the strategical and operational situation,” said the Joint Chiefs of Staff on Tuesday.

North Korea has sent over 1,000 balloons toward the South since May, which it calls reprisals for South Korean activists flying leaflets that contain materials critical of the regime of its leader Kim Jong Un.

On Thursday, a South Korean advocacy group flew 20 large balloons carrying thousands of anti-North Korean propaganda leaflets and USB sticks with South Korean entertainment toward North Korea. A day later, on Friday, Kim Yo Jong, the powerful sister of North Korea’s leader, warned of “trouble” ahead.

“When you do something you were clearly warned not to do, it’s only natural that you will find yourself dealing with something you didn’t have to,” she said.

A South Korean analysis of North Korean balloons sent between late May and early June detected parasites in the balloons’ soil, which “may have originated from human feces,” the ministry said, pointing to “human genes” found in the soil.

The analysis found roundworms, whipworms and larva currens along with other waste, such as cloth and wastepaper, the ministry said, adding there was no risk of contamination or infectious disease from the analyzed soil.

The balloons also carried damaged clothes from a South Korean brand, signaling “hostility towards South Korean goods,” as well as clothes with imitations of Disney characters, according to the ministry.

The latest balloon salvo comes as tensions on the Korean Peninsula heighten, and inter-Korean diplomacy remains at an impasse. Russian President Vladimir Putin signed a defense agreement with North Korea last week as talks on its denuclearization efforts have stalled, and Kim has vowed to expand his country’s nuclear arsenal and threatened to use it against the South.

In the meantime, a US Navy aircraft carrier arrived in South Korea over the weekend ahead of trilateral exercises with South Korea and Japan in the waters near the peninsula. It is the latest in a series of US military moves aiming to affirm Washington’s “ironclad” commitment to its treaty ally in South Korea.

US and South Korean officials signed a new memorandum of understanding on diplomatic intelligence sharing and analysis on Monday, according to South Korea’s foreign ministry.

Japanese, South Korean and U.S. officials also held a trilateral call where they issued a joint statement that called the deepening security cooperation between Russia and North Korea a matter of “grave concern” to those seeking to maintain peace on the Korean Peninsula.

“The United States, ROK, and Japan condemn in the strongest possible terms deepening military cooperation between the DPRK and Russia, including continued arms transfers from the DPRK to Russia that prolong the suffering of the Ukrainian people, violate multiple United Nations Security Council Resolutions, and threaten stability in both Northeast Asia and Europe,” the statement said.