TOKYO — A pre-dawn fire raged through an adult video theater in the western Japanese city Osaka, killing at least 15 people and injuring 10 others, police and fire department officials said Wednesday.

Police arrested one of the customers on suspicion of arson and attempted murder, Osaka police spokesman Kengo Hirami said. The suspect admitted to police that he set fire using a stash of newspapers in his bag.

The blaze broke out at about 3 a.m. (1800 GMT) in the Cats Adult Video Theater, located on the ground floor of a seven-story building in an entertainment district in Japan’s second-largest city, fire department official Yuko Kotani said.

Hirami said officials were still trying to determine the identities of the 15 dead. Officials said 10 of the injured were being treated at a nearby hospital, and several were in serious condition.

When the fire started, most of the theater’s 32 viewing cubicles — each equipped with a cot, a television and a DVD player — were occupied.

The video center offered a wide selection of DVDs, mostly adult movies, but also cartoons and Hollywood films, and attracted businessmen and others who used the rooms as a cheap alternative to hotels after missing the last train home.

A growing number of young people whose low-paying jobs cannot pay for proper housing live in such all-night lounges watching videos or reading comic books.

In 2001, a building fire in Tokyo’s biggest red-light district killed more than 40 people, including bar hostesses and their customers.