Thirty-seven people suspected of illegal mining have died in custody in north-central Nigeria, local officials have confirmed. The deaths occurred in a detention facility in Niger state, run by the Nigerian Security and Civil Defence Corps (NSCDC).
Police have launched an investigation into the deaths. The NSCDC initially attributed the deaths to a possible diphtheria outbreak, but its national headquarters later stated the cause had not been established and requires medical and laboratory tests.
However, an intelligence report shared with AFP news agency suggested the group died due to overcrowding and poor ventilation within the facility. The father of one detainee told the BBC that his son described how detainees began collapsing in the heat of the overcrowded cell and repeatedly knocked for help.
Niger state governor Mohammed Umaru Bago called the deaths "sad and tragic" and announced that an NSCDC commander has been detained. He also declared three days of mourning and postponed election campaigning.
The individuals were arrested on Tuesday for suspected illegal mining near Borgu. Post-mortem examinations are expected to help establish the cause of death, and the bodies have been taken to a general hospital for examination.