South Korea says it will restart anti-North Korean propaganda loudspeaker broadcasts in border areas in response to continuing North Korean campaigns to drop rubbish on the South with balloons.

Following an emergency security meeting led by South Korean national security director Chang Ho-jin, the officials decided to install and begin the loudspeaker broadcasts in border areas, Seoul’s presidential office said in a statement on Sunday.

The move is certain to anger North Korea and potentially prompt it to take retaliatory military steps.

With the loudspeakers, South Korea may blare anti-Pyongyang broadcasts, K-pop songs and outside news across the rivals’ heavily armed border. North Korea is extremely sensitive to such broadcasts because it fears it could demoralise front-line troops and residents and eventually weaken leader Kim Jong Un’s grip on power, analysts say.

In 2015, when South Korea restarted loudspeaker broadcasts for the first time in 11 years, North Korea fired artillery rounds across the border, prompting South Korea to return fire, according to South Korean officials. No casualties were reported.

Chang and other South Korean security officials berated Pyongyang for attempting to cause “anxiety and disruption” in South Korea and stressed that North Korea would be “solely responsible” for any future escalation of tensions between the Koreas.

North Korea over the weekend flew hundreds of rubbish-carrying balloons to South Korea in its third such campaign since late May, the South’s military said, just days after South Korean activists floated their balloons to scatter propaganda leaflets in the North.

North Korea has so far sent more than 1,000 balloons to drop tonnes of rubbish and manure in the South in retaliation against South Korean civilian leafleting campaigns, adding to tensions between the war-divided rivals amid a diplomatic deadlock over the North’s nuclear ambitions.

The resumption of South Korea’s loudspeaker broadcasts has been widely anticipated since last week, when South Korea suspended a 2018 tension-easing agreement with North Korea. The move allowed for the South to resume propaganda campaigns and possibly restart live-fire military exercises in border areas.

South Korea’s Joint Chiefs of Staff said it detected the North launching about 330 balloons towards the South since Saturday night and about 80 were found in South Korean territory as of Sunday morning. The military said winds were blowing eastwards on Saturday night, which possibly caused many balloons to float away from South Korean territory.

The South’s military said the balloons that did land dropped rubbish, including plastic and paper waste, but no hazardous substances were discovered.

The military, which has mobilised chemical rapid response and explosive clearance units to retrieve the North Korean balloons and materials, alerted the public to beware of falling objects and not to touch balloons found on the ground but to report them to police or military authorities.

Saturday’s balloon launches by North Korea were the third of their kind since May 28. In North Korea’s previous two rounds of balloon activities, South Korean authorities discovered about 1,000 balloons that were tied to vinyl bags containing manure, cigarette butts, scraps of cloth, waste batteries and waste paper. Some were popped and scattered on roads, residential areas and schools.

No highly dangerous materials were found and no serious damage has been reported.