Railway operators in Japan will restrict certain hazardous materials from being carried on board as part of a move to bolster security ahead of the 2025 Osaka Expo.

The Japan Private Railway Association, a group of 73 operators, and six JR companies plan to expand the list of restricted items to include materials such as flammable liquids, high-pressure gases, explosives, poisons and pesticides, the transport ministry said Tuesday.

The ministry ordered all railway companies to revise their anti-terrorism guidelines and ban hazardous chemicals that are currently allowed to be brought on board under certain conditions.