Ten students of The Polytechnic Ibadan in Oyo State have been hospitalised, DAILY POST reports.
Our correspondent gathered that the students collapsed after they inhaled the substance.
They were thereafter hospitalised. The students were evacuated and transferred to Ring Road State Hospital and the University College Hospital (UCH) all in Ibadan, following the incident.
The affected students, who are from the Science Laboratory and Technology Department, were seated in their lecture hall after a course test had been conducted.
A fight reportedly broke out between two students and while others attempted to intervene, an unknown choking substance was released into the air, allegedly sprayed by one of the students.
This led to several students collapsing, and some went unconscious.
Commissioner for Health, Dr Oluwaserimi Ajetunmobi, confirmed the development in a statement issued on Tuesday.
The commissioner urged the management of the institution to investigate the incident.
She advised the institution to ensure that those responsible are identified and brought to justice.