A balloon carrying garbage, presumably sent by North Korea, is seen floating on the Han River in Seoul on Sunday in this photo provided by the Joint Chiefs of Staff. (Yonhap)

North Korea launched more balloons, presumed to be filled with trash by the South Korean military, toward South Korea on Sunday night, the Joint Chiefs of Staff in Seoul announced.

The Seoul Metropolitan Government issued a public safety alert around 10:15 p.m. local time, stating that North Korea's trash-carrying balloons had entered the air above Seoul.

The balloon launch, marking the fourth such batch since May 28, took place after the South Korean military resumed broadcasting loudspeakers on the inter-Korean border on Sunday afternoon.

Seoul's action was a direct response to North Korea's earlier launches of 330 trash-laden balloons into South Korean territory, from late Saturday until Sunday morning.

The JCS earlier in the day issued a warning, stating that the decision to conduct additional loudspeaker broadcasts toward North Korea would depend entirely on North Korea's actions.

The decision to resume broadcasts was made at an emergency meeting of the presidential National Security Council's standing committee, convened by national security adviser Chang Ho-jin on Sunday.

The revival of North Korean loudspeaker broadcasts comes roughly six years after the dismantling and removal of both fixed and mobile loudspeakers. The dismantlement was the follow-up action to the Panmunjom Declaration signed by the leaders of the two Koreas on April 27.

Tensions between the two Koreas escalate over differing perspectives on balloon launches.

South Korea has vowed to take countermeasures against North Korea's release of trash-filled balloons, which North Korea alleges is retaliation for South Korean civic groups distributing anti-North Korea propaganda leaflets via balloons.

Following the first emergency meeting regarding North Korea's launch of approximately 1,000 trash-filled balloons between May 28 and June 2, along with GPS interference near the inter-Korean border, Chang announced on June 2 that South Korea would take "unendurable measures" if the launches persisted.

On June 2, North Korea issued a warning, threatening to retaliate by significantly increasing the dissemination of waste paper and rubbish, surpassing the quantity of leaflets and incidents instigated by South Korea, should these activities by civic groups persist.

North Korea's balloon launches over the weekend were apparently in response to South Korean activists' releases of leaflet-carrying balloons aimed at North Korea from Thursday to Friday.