ABUJA, Nigeria (AFP) — Poor jail conditions were responsible for the deaths of more than 30 miners in central Nigeria last month, following their arrest on suspicion of illegal gold mining by a paramilitary government agency, investigators said Tuesday.

The young men were found dead after they were thrown inside a crowded cell in Minna, the capital of central Niger state, in September after their arrest by the Nigeria Security and Civil Defence Corps (NSCDC).

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

Screams for help and banging the door yielded no response from guards on duty, according to survivors.

Medical and forensic evidence showed the deaths resulted from “environmental asphyxia, acute respiratory failure caused by prolonged confinement in a severely overcrowded and poorly ventilated detention cell aggravated by heat stress and dehydration”, the head of the investigating team, Jonathan Kure, said while presenting the report to the government.

Niger state authorities initially put the death toll at 37, but the investigating committee said it had established 33 deaths.

“The committee confirmed 33 as the verified casualty figure because higher numbers reported immediately after the incident could not be reconciled with available records and identified victims,” said Kure, adding that 14 of the dead were minors.