Dozens of people are feared dead after a blaze at a commercial building in western Japan, according to the NHK broadcaster.

The fire broke out on the fourth or fifth floor of an eight-story building in a shopping and entertainment area in the city of Osaka on Friday, NHK said.

A total of 28 people were "severely injured”, it said, with "most of them without vital signs.”

An official at Osaka city’s fire department told Reuters that 27 people were in cardiopulmonary arrest, the term used in Japan before a death is officially confirmed.

TV Asahi said nine people have been confirmed dead.

The fire was reported shortly after the clinic opened for business at 10am (0100 GMT) and was mostly extinguished within 30 minutes, NHK reported.

Videos broadcast on the network showed smoke pouring out of the building’s fourth floor windows, where a psychiatry clinic is located, and at the roof of the building.

Other floors of the building, which is near the Osaka’s main station in the centre of the city, were occupied by a beauty salon, a clothes shop and an English-language school, NHK said.

Police sources told Kyodo News they are investigating suspected arson, including reports that a man started a fire in the building.

An elderly man brought a bag into the building that leaked flammable liquid and was ignited, the Yomiuri newspaper said.

The man was believed to be a patient at the clinic, the Mainichi newspaper said.

One witness told Kyodo she saw "orange flames in the fourth-floor window” of the building and a woman "waving her hands for help from the sixth floor window”.

Another woman told Kyodo that power briefly went out in the surrounding area.

An arson attack at an animation studio in the city of Kyoto in 2019 killed more than 30 people and injured dozens.