One of the survivors of the incident in which 37 suspected illegal miners died in the custody of the Nigeria Security and Civil Defence Corps (NSCDC) in Minna, Niger State, has alleged that an unidentified substance was sprayed inside the overcrowded cell shortly before it was locked.

The survivor, who recounted his experience on Friday, said 17 detainees were initially kept in a small room before additional suspects were brought in, despite complaints about the size of the facility and the intense heat.

“They locked us in a very small room. We were 17 in number, then they added more people, and we started complaining that the room was small,” he said.

According to him, the situation worsened when the detainees were asked to stand as the room was about to be locked.

“As they were about to lock the room, they sprayed something that looked like perfume, and the smell started disturbing everyone in the room,” he alleged.

He said people subsequently began collapsing as the room became increasingly hot, adding that the detainees pleaded for water but were allegedly told that nobody would open the door.

“We pleaded with them to give us water, but they said no one would open the door for us,” he said.

Another survivor, who asked not to be identified, said he survived because he was close to the entrance of the cell, where he was able to breathe better.

“We were screaming for help,” he said, adding that guards were informed that “people are dying one after the other” but allegedly did not believe the detainees.

The deaths have triggered protests in Minna, with reports that demonstrators blocked a major road and attacked a transport depot.

It was not immediately clear whether police used live ammunition or anti-riot weapons to disperse the protesters.

President Bola Tinubu has ordered a full and transparent investigation into the deaths, saying no Nigerian should lose his or her life in government custody through negligence, abuse, inhumane treatment or dereliction of duty.

The Minister of Interior, Olubunmi Tunji-Ojo, also suspended the NSCDC Niger State Commandant, Suberu Siyaka Aniviye, pending investigation into the incident.

“A full investigation will be conducted while the commandant under whose watch this happened remains suspended,” Tunji-Ojo said.

An intelligence report cited by AFP reportedly suggested that overcrowding and poor ventilation may have contributed to the deaths, while the NSCDC had initially attributed them to disease.

Niger State Governor Umaru Bago subsequently imposed a nighttime curfew in Minna following the unrest triggered by the incident.