North Korea hinted Friday that it will send more trash-carrying balloons toward South Korea in protest of a North Korean defector group's flying of anti-Pyongyang propaganda leaflets north of the border.

In a statement carried by the state-run Korean Central News Agency(KCNA), Kim Yo-jong, the sister of North Korean leader Kim Jong-un, said dirty paper waste and items from the South were found scattered near the border once again.

She said the North requested a halt to the propaganda activity, but its resumption now requires the regime "to do something unnecessary." 

Kim said the "scums," in reference to the defectors, will face backlash from their countrymen. 

Earlier, Fighters for a Free North Korea, a defectors' group based in South Korea, announced that its members floated 20 balloons carrying propaganda leaflets, USBs, and U.S. one dollar bills across the border from the Gyeonggi city of Paju late Thursday. 

Between May 28 and June 9, Pyongyang sent over a thousand trash-filled balloons south of the border and threatened stronger retaliation should the leaflet activity continue. 

Seoul, in response, resumed loudspeaker propaganda broadcasts along the border.