Some 300 visitors fled Tuesday morning from the Aichi Expo Gas Pavilion after a piece of machinery caught fire shortly before a magic show, injuring an actor, police said.

No visitors were injured.

Entertainer Hidenao Kuboki, 28, was stuffing cotton laced with a flammable agent into the gadget backstage on the second floor of the Japan Gas Association Pavilion when it caught fire, causing minor burns to his face and shoulders, according to police and expo officials.

The fire was put out by another member of the pavilion with a fire extinguisher, they said.

The show, the second of the day at the Gas Pavilion, uses fire. Expo organizers said it was the first time visitors have been forced to evacuate a pavilion since the expo opened in March.