The operator of the 2025 World Exposition in Osaka has shown media a facility where methane exploded during construction work.

In March, sparks ignited the flammable gas, causing an explosion in the venue's northwestern area called the "Green World." One hundred square meters of concrete floor were damaged. The operator later explained there was methane in the ground there as it was a landfill site.

Surveys later also detected methane below the level of the legal standard at five locations in the eastern area called the "Pavilion World."

On Tuesday, the Japan Association for the 2025 World Expo showed media the concrete floor damaged by the explosion as well as areas where the gas was detected.

Officials explained safety measures that are being taken, including installing fans to vent the gas. They also said they will continue to gauge gas levels and release the data on its website on a daily basis during the event to dispel visitor concerns.

An official said since concern seems exaggerated, the association will explain facts and safety measures to reassure people.