A 61-year-old man in Japan is the prime suspect in a fire that killed 24 people at a mental health clinic where he was a patient, police say

• A fire broke out at a mental health clinic in Osaka, Japan, on Friday, killing 24 people.
• Police said they identified the suspect through security camera footage and his patient card for the clinic.

On Sunday, Japanese police identified a 61-year-old man as a prime suspect in their investigation into a fire that killed 24 people at a mental health clinic in Osaka on Friday, the Associated Press reported.

Police are treating the fire as an arson and murder case and have named Morio Tanimoto as the primary suspect. Tanimoto, who is currently being treated and is in serious condition after being rescued from the fire, has not been arrested or charged, according to AP.

An anonymous official at the local police department told AP that investigators used security cameras to track the suspect and searched the home of Tanimoto on Saturday, where they found a patient card for the clinic.

On the day of the fire, patients were attending counseling sessions for people who had recently taken sick leave and were preparing to re-enter the workforce, The Asahi Shimbun reported.

Survivors of the fire told police a man placed a paper bag on the floor next to a heater prior to the fire, leading investigators to find traces of a highly flammable liquid, the Asahi Shimbun reported.

Investigators are still conducting forensic tests to identify the substance. However, the fire's speed and traces it left in the clinic led investigators to believe the fire was intentionally set, the Asahi Shimbun reported.

Internal Affairs and Communications Minister Yasushi Kaneko said on Sunday that the victims could not escape because the fire made the building's sole stairway inaccessible. As a result, Kaneko ordered a nationwide inspection of nearly 30,000 commercial buildings with only one stairway, AP reported.