According to the report, "the number of criminal investigations and cases prosecuted by the government for labor trafficking and child sex trafficking remained low." "A majority of child sex traffickers (were allowed) to operate with impunity," it said. The report called on the government to "vigorously investigate and prosecute sex and labor trafficking and seek adequate penalties for convicted traffickers." The human trafficking report maintained China in the lowest ranking. It said, "there was a government policy or pattern of widespread forced labor" involving Uighurs and members of other ethnic minority groups in the Xinjiang Uighur Autonomous Region "under the guise of 'vocational training' and 'deradicalization.'" Other countries in the same group include North Korea, Russia and Iran. In East Asia, South Korea was upgraded to Tier 1. In Southeast Asia, Vietnam was upgraded to Tier 2.