NEW : A Colombian mining agency says 20 miners are dead . The bodies were found in a mine near the town of La Esperanza, about 100 miles from Bogota. The agency says six miners were injured . At least 20 people were killed and six injured Wednesday in a mine explosion in northeastern Colombia near the border with Venezuela , the government-run Colombian Institute of Geology and Mining , known by the acronym Ingeominas , reported . The blast happened near Colombia 's border with Venezuela . A build-up of methane gas may be to blame , governor says .
NEW : A Colombian mining agency says 20 miners are dead . The bodies were found in a mine near the town of La Esperanza, about 100 miles from Bogota. The agency says six miners were injured . The blast happened near Colombia 's border with Venezuela . A build-up of methane gas may be to blame , governor says .