Seoul, June 6 : A North Korean defectors' group said on Thursday that it has sent about 10 large plastic balloons carrying propaganda leaflets against the North Korean regime across the border, raising concerns Pyongyang could resume sending trash-filled balloons.

Filled with 200,000 flyers criticising the regime, dollar bills and USB sticks loaded with K-pop and trot music, the balloons were floated from Pocheon, north of Seoul, early Thursday, according to Park Sang-hak, head of the Fighters for a Free North Korea (FFNK).

A military source confirmed that some of these balloons have flown into North Korea but said no signs of retaliatory action were detected yet from the North Korean side, including any launch of ballistic missiles or release of balloons loaded with trash, Yonhap news agency reported.

The military is also closely monitoring North Korea for signs of provocations, a Joint Chiefs of Staff official said.

A Unification Ministry official said the Ministry is maintaining close communication with the relevant agencies and "doing its best to manage the situation".

Since last week, Pyongyang has sent nearly 1,000 balloons carrying trash to South Korea in what it called a "tit-for-tat" action against such anti-Pyongyang leaflet campaigns.

After the South Korean government on Sunday warned of "unendurable" measures, including resuming loudspeaker broadcasting, the North Korea said it will temporarily halt dropping balloons across the border.

North Korea, however, also warned it will send "a hundred times the amount of toilet paper and filth" of what the South Korea sends, raising concerns the reclusive country could start the waste-filled campaign again.

The FFNK has sent balloons carrying similar goods across the border although such acts are banned in South Korea under a law that was legislated during the previous administration to help reduce tensions in the border regions.

/IANS