North Korea sent more trash balloons over the South Korean border early Monday morning. 

The South Korean Joint Chiefs of Staff(JCS) said the North began another balloon launch around 3 a.m. Monday and that the balloons are likely to drift toward Seoul and Gyeonggi Province, considering the direction of the wind.

The latest launch comes about three weeks after the previous one. 

Since May 28, the North has launched thousands of balloons on 31 occasions, with bags of trash attached to each one.

Monday’s launch comes a day after Kim Yo-jong, the powerful sister of North Korean leader Kim Jong-un, warned that South Korea would pay a “dear price” for sending propaganda leaflets across the border on Saturday.