At least seven people were killed Friday when a gold mine collapsed in the south-western Colombian province of Narino, the Colombian TV network Caracol reported according to dpa.A further 15 people were missing in the accident, which also injured 31, Caracol said.The accident happened at a mine that the report said operated without the necessary permits just outside the town of Iscuande, which isabout 500 kilometres south-west of Bogota. Such mines exist throughout the Andes.The worst mining accident in Colombian history happened in mid-2010, when 73 workers died in a blast at a coal mine in Amaga in the north-western province of Antioquia.