A Thai fireman turned superhero when he dressed up as comic-book character Spider-Man to coax a frightened eight-year-old from a balcony, police said on Tuesday.

Teachers at a special needs school in Bangkok alerted authorities on Monday when an autistic pupil, scared of attending his first day at school, sat out on the third-floor ledge and refused to come inside, a police sergeant told AFP.

Despite teachers' efforts to beckon the boy inside, he refused to budge until his mother mentioned her son's love of superheroes, prompting fireman Sonchai Yoosabai to take a novel approach to the problem.

The rescuer dashed back to his fire station and made a quick change into a Spider-Man costume before returning to the boy, he said.

"I told him Spider-Man is here to rescue you, no monsters are going to attack you and I told him to walk slowly towards me as running could be dangerous," Somchai told local television.

The young boy immediately stood up and walked into his rescuer's arms, police said.

Somchai said he keeps the Spider-Man costume and an outfit of Japanese television character Ultraman at the station in order to liven up school fire drills.

AFP