France, Sept. 19 -- Police have set up an investigation into the deaths, which the Nigerian Security and Civil Defence Corps (NSCDC) initially blamed on an outbreak of disease, the interior ministry announced Saturday.

Thirty-seven young men were found dead inside a crowded cell in Minna, the capital of central Niger state, on Thursday after their arrest on suspicion of illegal gold-mining by the NSCDC.

Survivors recounted being crammed in the cell with poor ventilation, and one said a substance that stung their throats and noses was sprayed into the cell before the door was slammed shut.

They said their calls for help were ignored. A person arranges the bodies of the illegal mining suspects arrested in mining raids who reportedly died...