North Korea has publicly executed at least seven people in the past decade for watching or distributing K-pop videos from South Korea, as it cracks down on what its leader, Kim Jong-un, calls a “vicious cancer,” according to a human rights report released on Wednesday.

​The group, ​ Transitional Justice Working Group, which is based in Seoul, interviewed 683 North Korean defectors since 2015 to help map places in the North where people were ​killed and buried​ in state-sanctioned public executions​. In its latest report, the group said it had documented 23 such executions under Mr. Kim’s government.

Since taking power a decade ago, Mr. Kim has attacked South Korean entertainment — songs, movies and TV dramas — which, he says, corrupts North Koreans’ minds. Under a law adopted last December, those who distribute South Korean entertainment can face the death penalty. One tactic of Mr. Kim’s clampdown has been to create an atmosphere of terror by publicly executing people found guilty of watching or circulating the banned content.