By JON HERSKOVITZ | Bloomberg | Published: February 26, 2021 North Korea has stepped up its use of forced labor from prison camps to mine coal for export so it can procure cash for its nuclear weapons program in defiance of United Nations sanctions, according to a human rights group. Satellite imagery shows an expansion of some prison camps near mines that has coincided with global sanctions being ratcheted up on Kim Jong Un’s regime to punish it for its nuclear weapons programs, according to a report released Friday by the Citizens Alliance for North Korea Human Rights, a Seoul-based group that has participating in United Nations reviews of North Korea’s rights record.