Authorities in Ogun State have launched an extensive investigation into a series of mysterious gas emissions that have affected more than 200 students and teachers across several schools in Ijebu-Ode over the past two months.

The recurring incidents, which have triggered panic among residents and disrupted academic activities, are believed to be linked to underground geological activity, according to state officials.

The latest outbreak occurred on June 3 at Our Lady of Apostles Secondary School, where a strong, pungent odour spread through classrooms during school hours. Students and staff reportedly experienced breathing difficulties, persistent coughing, dizziness, and fainting, prompting an emergency evacuation.

Affected students were taken to the State General Hospital in Ijebu-Ode for treatment, while authorities temporarily suspended academic activities at the school.

The June incident was the third such occurrence recorded in the town since April.

According to state officials, the first outbreak was reported on April 1 at Our Lady of Apostles Secondary School, where at least 30 students and two teachers were hospitalised after inhaling an unidentified gas.

A second and more widespread episode occurred on May 15, affecting several schools, including Anglican Girls Grammar School, Ijebu-Ode Grammar School, and Sambadola Private School. More than 90 students reportedly fell ill during the incident, which prompted emergency environmental assessments in the area.

Air quality monitoring conducted during the May outbreak detected elevated methane levels, with concentrations reportedly reaching approximately 13,500 parts per million.

Ogun State Commissioner for Health, Dr. Tomi Coker, said all affected students and staff members who received medical attention have since been treated and discharged.

She explained that while methane is generally considered non-toxic, high concentrations can reduce oxygen levels in the environment, potentially causing symptoms such as dizziness, breathing difficulties, and loss of consciousness.

As investigations intensified, officials from the Ministry of Environment ruled out initial suspicions of industrial accidents or laboratory-related incidents.

Commissioner for Environment Ola Oresanya said data collected through gas monitoring equipment and drone surveillance indicated that the affected schools are located along the same underground corridor.

According to preliminary findings, experts suspect the emissions may be linked to a subsurface geological fault line beneath parts of Ijebu-Ode. Authorities believe natural underground gases, primarily methane and traces of hydrogen sulphide, may be escaping through fractures in the earth’s crust.

In response to the recurring incidents, the Ogun State Government has suspended commercial gas pipeline activities within the affected area as a precautionary measure pending the outcome of ongoing investigations.

The state has also deployed medical teams, emergency response personnel, ambulances, and air-quality monitoring systems to schools considered vulnerable to future outbreaks.

Officials said efforts are ongoing to determine the exact source of the emissions and implement long-term measures to prevent further incidents.

Despite the scale of the outbreaks, authorities confirmed that no fatalities have been recorded, while more than 200 students and staff members affected across the various incidents have recovered after receiving medical care.

The investigation continues as environmental experts seek to establish whether natural geological processes or other factors are responsible for the unusual gas emissions.