Propaganda leaflets, likely sent by balloons from North Korea, were found in central Seoul over the weekend, one of which contains sexually explicit cartoons depicting now-impeached South Korean President Park Geun-hye.

The leaflets were found on the way from Grand Hyatt Seoul hotel to the Hannam-dong neighborhood of South Korea’s capital, and are part of an apparently escalating campaign by the North to spread its message in the South.

“This present campaign may be the longest sustained balloon initiative on the part of the North Korean government in the past 10 years—or, more accurately, the most successful initiative in terms