Fire fighters are trying to put out a blaze that has been burning since Thursday night at a coal museum in the city of Yubari in Japan's northern prefecture of Hokkaido.
An employee at Yubari Coal Museum discovered the fire late at night, saying smoke was coming out of a tunnel, located beneath the building.
The tunnel was once part of a coal mine. It is now an attraction used to highlight Japan's coal industry to visitors and tourists.
Five fire trucks have been deployed to extinguish the fire, but white smoke continues to billow out of the building as of Friday morning.
Fire officials suspect that a layer of coal below the building is burning. On Thursday, workers were doing welding work to reinforce the tunnel in preparation for the museum's seasonal opening scheduled later this month.
They say workers left the tunnel early evening, and no one was there when the fire broke out.
The coal museum opened in 1980 to showcase Japan's coal industry that helped spur the country's industrialization. Its renovation cost about 4.5 million dollars.