North Korea has publicly executed some 60 people so far this year, as its leader Kim Jong-un strengthens his grip on power, South Korea’s Yonhap News Agency reported on Friday.

“As of August, the North is believed to have carried out the public execution on about 60 ordinary people,” an anonymous source was quoted as saying. “The figure is two times higher than the annual average of 30 people executed per year since the North’s leader took office.”

Since taking power in 2011, Kim Jong-un has removed or demoted a large number of top-ranking officials and military leaders.