The blaze broke out in the three-story building in the Japanese capital's Shibuya district in the afternoon, and spread to several neighboring structures. TV footage showed the gutted building with a column of smoke rising from it.

The facility contained gunpowder and residents told firefighters they heard a large explosion just before the deadly blaze started, the spokesman said on condition of anonymity, citing department policy.

Police were investigating the exact cause of the fire. -- AP