TOKYO, Oct. 31 (Xinhua) -- The main building of the Shuri Castle in Japan's Okinawa, also a World Heritage site, has burned down in a fire, with authorities working to control the blaze that has also engulfed other buildings, the police said on Thursday.

The fire started shortly before 2:40 a.m. local time at Shuri Castle in Naha, the prefectural capital of Okinawa. The police and a local fire department said more than 10 fire engines have been dispatched.

The police are investigating the cause of the fire and there were no immediate reports of injuries.

The castle, listed as Japan's 11th World Heritage site in December 2000, is a major tourist spot in the southwestern Japan prefecture.