A fire broke out Thursday night at a hotel in Tokyo's Kabukicho entertainment district, killing a female guest in her 60s, according to police and the fire department.

The fire started at around 6:30 p.m. at the five-story Hotel Matsuki, and the guest was found in her room on the second floor, they said. She was taken to a hospital, but was confirmed to have died from carbon monoxide poisoning. She was the only guest at the hotel.

Members of the owner's family who were in the hotel checked the building when a fire alarm went off and discovered the fire had broken out around the front desk area on the first floor, the Tokyo Fire Deparment said.

According to news reports, the hotel was not equipped with water sprinklers because its total floor space was less than what is legally required for such equipment.

"At first, smoke came out from the first floor, and flames came up a little later," said Tamotsu Tokuhara, 70, who runs a restaurant nearby. "I heard blasts many times and flames burst out every time a blast (occurred)."

The police are investigating to determine the cause of the blaze.