A huge fire has broken out at a steel plant by Haneda Airport, south of the Japanese capital Tokyo.

A fire official told AFP that the blaze broke out at a two-metre high cooling tower owned by Nippon Steel. 600 employees were evacuated after the inferno spread to a factory next door. There have been no reports of injuries, according to officials.

A video posted online by Twitter uses Darren Pauls shows the huge plumes of black smoke caused by the fire emenating near the airport runway. He also commented on the social media site that services at the airport appeared unaffected.

The fire caused minor delays to some flights at the airport. Haneda Airport, located 25km (15 miles) from central Tokyo, is the busiest airport in Japan and forth busiest in the world, after Hartsfield-Jackson Atlanta International Airport, Beijing Capital International Airport and London Heathrow Airport.

A second fire was reported in Tokyo on the same day, with a nearby US military base in Sagamihara suffering several explosions. The cause of that fire is not immediately known.