SOUTH KOREA took steps today to suspend a contentious military agreement with North Korea, as tensions between the rivals rise over the North’s recent launch of rubbish-carrying balloons.

Pyongyang didn’t immediately respond, but South Korea’s resumption of firing exercises or propaganda loudspeaker broadcasts will likely prompt the North to take similar or stronger steps along the tense border.

In the past week, North Korea has used balloons to drop manure, cigarette butts, scraps of cloth and waste paper on South Korea, prompting Seoul to vow “unbearable” retaliation.