A massive fire ripped through a psychiatry clinic in Osaka, Japan, on Friday after a patient carried a bag into the building that was leaking flammable liquid.
Reuters, citing the Yomiuri newspaper, described the patient as an elderly man. Other reports said police in the city were investigating possible arson. Twenty-seven people are feared dead.
All of them have since been taken to nearby hospitals.
Four people have been pronounced dead, NHK national television and other media reported, but Japanese authorities declined to confirm.
The Associated Press reported the building houses an internal medicine clinic, an English language school and other businesses.
"We don’t know the details yet, but small multi-tenant buildings sometimes have only one emergency staircase," Ai Sekizawa, an expert on fires at Tokyo University of Science, told NHK, according to the New York Times. He called the fire "shocking."
The Associated Press contributed to this report