Four people died and at least 19 people were injured in a fire at a game center in the city of Osaka on Sunday afternoon, local press reported, quoting police and firefighter sources.
They are still investigating whether there are other people who failed to escape from the game parlor, they said, while some reports said a man around 30 years old had started the fire.
The police said they have started an investigation into the fire as a case involving murder and arson, accordint to Kyodo News.
The four dead are a man in his 60s and three women, while five of the 19 injured were in serious condition, the firefighters said.
Witnesses reported seeing one woman fleeing from the building with her back on fire.
When the fire started at around 4:10 p.m., some 100 people, including employees, were in the parlor, while another 30 people were on the upper floors.
Around 50 fire engines and one helicopter battled the fire and extinguished it about 25 minutes later, Kyodo said.
A 28-year-old office worker said he saw a man around 30 years old hanging around the pachinko parlor with a can of kerosene in the basket at the front of his bicycle shortly before the fire broke out. "I wondered why the man was carrying it in the summer," he said.